Daniel Mansell

Call: 2012

“Daniel is an outstanding junior. He has the rare ability to be both intellectually very sharp and also excellent with clients.”

Legal 500 2025: Inquests & Inquiries

“Daniel is devastatingly fair, very measured and effective.”

Chambers UK 2025: Professional Discipline

“Daniel is legally sharp. Even if he has a difficult point to pursue he does not give up or take a step back.”

Legal 500 2025: Professional Discipline

“A very impressive barrister who displays every quality of a member of the Bar, including an immensely persuasive advocate style. Daniel is a good all-rounder.”

Chambers UK 2024: Professional Discipline

“He is exceptional. Bright, funny, intelligent and incredibly easy to get on with.”

Chambers UK 2022: Professional Discipline

Daniel Mansell has a broad practice across chambers’ areas of expertise, specialising in professional discipline, crime and major public inquiries.

He has worked on some of the most important public inquiries of recent times, including the Grenfell Tower Inquiry, the Independent Inquiry into Child Sexual Abuse (IICSA), the Manchester Arena Inquiry and the Dawn Sturgess Inquiry (which concerns the Salisbury Novichok poisonings). He is currently instructed as a member of the Counsel to the Inquiry team for the UK Covid-19 Inquiry.

Daniel is regularly instructed in the field of professional discipline, representing both regulators and registered professionals. He has acted in proceedings brought by, among others, the General Medical Council (GMC), General Dental Council (GDC), the Health and Care Professions Council (HCPC), the General Optical Council (GOC), the Nursing and Midwifery Council (NMC) and the Solicitors Regulation Authority (SRA). He also acts for police officers facing gross misconduct proceedings. Daniel advises at all stages of proceedings and is experienced in cross-examining experts.

He has extensive experience before the criminal courts, both prosecuting and defending. He has acted in cases involving serious violence, rape, sexual assault, drugs and fraud. Daniel represents a range of clients, including individuals, companies and statutory bodies.

Daniel has been appointed to List C of Specialist Regulatory Advocates and appeared in the case of R (West Coast Railways Company Ltd) v Office of Rail and Road [2023] EWHC 3338 (Admin). In this case, Daniel, led by Hugh Davies KC, represented the safety regulator for Britain’s railways, the Office of Rail and Road, in a successfully defended judicial review claim brought by West Coast Railway Company Ltd. West Coast is the largest operator of heritage train tours in the UK and runs a number of well-known services including the Flying Scotsman and the Jacobite steam train, known popularly as the “Hogwarts Express” having featured in the Harry Potter films. The case concerned the ORR’s decision not to grant West Coast an exemption from the general prohibition on hinged door trains.

Legal Expertise

Professional Discipline and Regulatory overview

Daniel has extensive experience in the field of healthcare regulation, representing both regulators and registrants. He appears before the General Medical Council (GMC), General Dental Council (GDC), General Optical Council (GOC), Nursing and Midwifery Council (NMC) and the Health and Care Professions Council (HCPC). Daniel is a Specialist Regulatory Advocate in Health & Safety and Environmental Law (list ‘C’).

Daniel regularly represents the General Dental Council in cases of alleged misconduct concerning dentists and other dental care professionals. These cases typically involve complex clinical issues and the cross-examination of experts. Daniel is often instructed early in the investigation process, providing advice on all stages leading up to the final hearing.

In 2015, Daniel undertook a nine-month secondment with the Regulatory and Professional Discipline department of Kingsley Napley LLP, acting for the the Health and Care Professions Council at fitness to practise hearings across the UK. Daniel presented cases against a range of professionals including paramedics, chiropodists, dietitians, physiotherapists, psychologists, occupational therapists, radiographers, social workers and biomedical scientists. These cases often involved technically complex allegations, vulnerable witnesses and expert evidence.

Notable Professional Discipline and Regulatory cases

SRA v T

Representing a solicitor facing allegations of dishonesty before the Solicitors Disciplinary Tribunal and on appeal at the High Court. Led by Alisdair Williamson KC.

GDC M

Representing the GDC in a case involving a dentist accused of behaving in a sexually inappropriate manner towards patients, including straddling one while she was in the dentist’s chair.

GDC H

Representing the GDC in a case involving allegations against a dentist of providing poor standards of treatment. The case involved a range of alleged clinical failings and conflicting expert evidence.

HCPC v A, B & C

Representing the HCPC at a three-week case against three registrant social workers. This factually complex case involved a range of failings involving a child who had been murdered by her mother.

Crime overview

Daniel has extensive experience in criminal matters, appearing in the Magistrates’ Courts and Crown Court for both the prosecution and defence. He has acted in connection with a range of offences including fraud, importation of cocaine, rape, malicious communications and serious violence. Daniel has extensive experience in relation to motoring offences. He has provided written advice on a wide variety of criminal matters, including blackmail.

As well as acting for the Crown Prosecution Service, Daniel represents other prosecution authorities and public bodies, such as Transport for London and the Information Commissioner’s Office. Daniel represents clients in a range of civil/quasi-criminal regulatory matters, including cash forfeiture hearings and sexual risk order hearings.

Daniel has been appointed to List C of Specialist Regulatory Advocates instructed by, among others, the Health and Safety Executive. He has acted for restaurants in relation to food hygiene prosecutions.

Notable Crime cases

R v L

Acting for a defendant charged with inflicting grievous bodily harm following an argument with a player on an opposing team at a five-a-side football match. The court heard evidence from five prosecution eyewitnesses. The defence of self-defence was successful and the defendant was acquitted.

R v S

Successfully argued that the M’Naghten rules (M’Naghten’s Case (1843)) applied to the defendant and that he was legally insane at the time he had attacked two police officers. The defendant was acquitted.

R v A

Representing a defendant in a case involving multiple charges of rape and sexual assault. The case involved Daniel sensitively cross-examining the child complainant. The defendant, a youth, was given a Referral Order.

R v A

Representing a defendant facing an obligatory three-year disqualification from driving after failing to provide a sample. Daniel successfully argued that “special reasons” applied and the defendant was instead given 6 penalty points.

Inquests & Inquiries overview

Daniel appears for interested persons in inquests and has worked on major public inquiries. He is well-versed in advising lay and professional clients on a range of issues, including disclosure and legal professional privilege. Daniel’s experience encompasses document-heavy cases and means he is proficient in the e-disclosure software Relativity.

Notable Inquests & Inquiries cases

Covid-19 Inquiry

Member of the Counsel to the Inquiry team for the inquiry into the UK’s response to, and impact of, the Covid-19 pandemic. Led by Richard Wald KC.

Manchester Arena Inquiry

Representing Greater Manchester Police and Counter Terrorism Policing North West in the public inquiry into the 2017 Manchester Arena terrorist attack. Led by Richard Horwell KC.

Inquest into the death of O

Inquest representing the Metropolitan Police in relation to a death in custody.

Licensing overview

Daniel represents licensed premises, the police and other interested persons in alcohol licensing applications. He has extensive experience of representing Transport for London in taxi licensing appeals brought at both the Magistrates’ Court and Crown Court. Daniel has acted in closure order proceedings.

Notable Licensing cases

The Wave: Licensing application

Representing local residents who were objecting to an application for an alcohol and entertainment licence made by a multi-million-pound artificial surfing lagoon.

R (on the application of Qin) v The Commissioner of the Police for the Metropolis [2017] EWHC 2750 (Admin)

Led by Stephen Walsh KC and acting for the Metropolitan Police in a judicial review in relation to a closure order application concerning multiple premises said to be operating as brothels. The case clarified the law on the notification requirements under the Anti-Social Behaviour, Crime and Policing Act 2014.

K

Licensing application. Representing a restaurant seeking an alcohol licence within a Cumulative Impact Area in West London. The licence was granted.

Professional discipline

SRA v T
Representing a solicitor facing allegations of dishonesty before the Solicitors Disciplinary Tribunal and on appeal at the High Court. Led by Alisdair Williamson KC.

GDC v M
Representing the GDC in a case involving a dentist accused of behaving in a sexually inappropriate manner towards patients, including straddling one while she was in the dentist’s chair.

GDC v M
Representing the GDC in a multi-faceted case encompassing clinical misconduct, impairment by reason of ill-health, impairment by reason of criminal conviction, and allegations of attending work while intoxicated.

GDC v P
Representing the GDC in a case involving a dentist who had sent threatening emails and behaved in an aggressive manner at a meeting with NHS staff.

GDC v H
Representing the GDC in a case involving allegations against a dentist of providing poor standards of treatment. The case involved a range of alleged clinical failings and conflicting expert evidence.

NMC v S
Acting for the registrant who faced a large number of serious allegations concerning the poor running of a care home. Daniel secured a favourable outcome as the panel only went so far as to impose a conditions of practice order.

HCPC v A
Representing the HCPC in a high-profile case concerning a former Kids Company psychologist who it was alleged had offered MDMA to a service user in a nightclub.

HCPC v A, B and C
Representing the HCPC at a three-week case against three registrant social workers. This factually complex case involved a range of failings involving a child who had been murdered by her mother.

HCPC v D
Representing the HCPC. It was alleged that the registrant physiotherapist had instigated an inappropriate sexual relationship with a patient.

HCPC v E
Representing the HCPC. This highly technical case involved a biomedical scientist failing to follow the correct procedure in relation to the analysis of calcium in a patient’s blood sample.

HCPC v F
Representing the HCPC. It was alleged that the registrant radiographer had dishonestly deleted mammogram images and not accurately recorded patient radiation exposure in order to make her appear more efficient.

HCPC v G
Representing the HCPC. This case involved an allegation that the registrant social worker had breached the confidentiality of a vulnerable service user who was subsequently murdered by her abusive partner.

Crime

R v A
Representing a defendant in a case involving multiple charges of rape and sexual assault. The case involved Daniel sensitively cross-examining the child complainant. The defendant, a youth, was given a Referral Order.

R v P
Appearing at Blackfriars Crown Court representing a defendant charged with a racially aggravated Public Order Act offence involving an altercation at a railway station. Daniel secured an acquittal from the jury despite the evidence of an independent prosecution eyewitness.

R v S
Successfully argued that the M’Naghten rules (M’Naghten’s Case (1843)) applied to the defendant and that he was legally insane at the time he had attacked two police officers. The defendant was acquitted.

R v G
Representing a defendant charged with obstruction of the highway during the protests outside parliament on the night of the House of Commons vote on military intervention in Syria. The case involved argument concerning human rights, specifically the right to freedom of expression.

R v G
Representing a defendant charged with racially aggravated offences at Cambridge Crown Court. Jury acquitted on all racially aggravated counts.

R v T
Secured the acquittal of a defendant charged under the Malicious Communications Act 1988.

London Borough of Camden v R
Representing a defendant charged in her capacity as a company director for failing to comply with housing regulations. Daniel presented detailed written legal argument concerning the statutory test for imposing criminal liability on company directors. Following this the prosecution dropped the case.

R v L
Acting for a defendant charged with inflicting grievous bodily harm following an argument with a player on an opposing team at a five-a-side football match. The court heard evidence from five prosecution eyewitnesses. The defence of self-defence was successful and the defendant was acquitted.

R v A
Representing a defendant facing an obligatory three-year disqualification from driving after failing to provide a sample. Daniel successfully argued that “special reasons” applied and the defendant was instead given 6 penalty points.

R v N
Acting for a police officer charged with common assault. Daniel highlighted a number of flaws with prosecution disclosure and the case was dropped.

R v N
Representing a defendant accused of common assault and possession of an offensive weapon. Defence of self-defence and lack of intent was successful and the defendant was acquitted.

R v M and M
Acting for two defendants from the same family charged with Public Order Act offences. Daniel challenged the public interest in bringing the case and the prosecution withdrew the charges.

Inquiries and inquests

Covid-19 Inquiry
Member of the Counsel to the Inquiry team for the inquiry into the UK’s response to, and impact of, the Covid-19 pandemic. Led by Richard Wald KC.

Dawn Sturgess Inquiry
Instructed by the Metropolitan Police Service in the public inquiry concerning the death of Dawn Sturgess (who died in Salisbury from Novichok poisoning).

Manchester Arena Inquiry
Representing Greater Manchester Police and Counter Terrorism Policing North West in the public inquiry into the 2017 Manchester Arena terrorist attack. Led by Richard Horwell KC.

Inquest into the death of O
Inquest representing the Metropolitan Police in relation to a death in custody.

Grenfell Tower Inquiry
Disclosure junior instructed by the London Fire Brigade.

Independent Inquiry into Child Sexual Abuse
Disclosure junior instructed by the Catholic Archdiocese of Birmingham.

Licensing

The Wave: licensing application
Representing local residents who were objecting to an application for an alcohol and entertainment licence made by a multi-million-pound artificial surfing lagoon.

R (on the application of Qin) v The Commissioner of the Police for the Metropolis
[2017] EWHC 2750 (Admin)
Led by Stephen Walsh KC and acting for the Metropolitan Police in a judicial review in relation to a closure order application concerning multiple premises said to be operating as brothels. The case clarified the law on the notification requirements under the Anti-Social Behaviour, Crime and Policing Act 2014.

K: licensing application
Representing a restaurant seeking an alcohol licence within a Cumulative Impact Area in West London. The licence was granted.

Daniel is devastatingly fair, very measured and effective.”  Chambers UK 2025:  Professional Discipline

“His advocacy is great.”  Chambers UK 2025:  Professional Discipline

“Daniel is an outstanding junior. He has the rare ability to be both intellectually very sharp and also excellent with clients.”  Legal 500 2025:  Inquests & Inquiries

“Daniel is legally sharp. Even if he has a difficult point to pursue he does not give up or take a step back.”  Legal 500 2025:  Professional Discipline

“He is incisive, thorough and very responsive. I know if Dan is the advocate on my case, everything is going to be okay.”  Chambers UK 2024:  Professional Discipline

“Superb at handling clients. He gets to the key issues and focuses on them. He’s a very good advocate both in writing and orally.”  Chambers UK 2024:  Professional Discipline

“A very impressive barrister who displays every quality of a member of the Bar, including an immensely persuasive advocate style. Daniel is a good all-rounder.”  Chambers UK 2024:  Professional Discipline

“He is incredibly hard-working and bright.”  Chambers UK 2023:  Professional Discipline

“He is exceptional. Bright, funny, intelligent and incredibly easy to get on with.”  Chambers UK 2022:  Professional Discipline

“A very safe pair of hands and a very good prosecutor. Always super organised and on top of his brief.” Chambers UK 2022:  Professional Discipline

Always super organised and on top of his brief.”   Chambers UK 2022:  Professional Discipline

“He is a really good prosecutor who is very fair.”   Chambers UK 2021:  Professional Discipline

“He is an excellent professional who has a very good and balanced tone in his advocacy. His cross-examination is firm, courteous and balanced.”  Chambers UK 2021:  Professional Discipline

  • Bar Professional Training Course (Outstanding)
  • LLB (First)
  • MA (Cantab) Queens’ College, Cambridge
  • Middle Temple Certificate of Honour (2012, for BPTC results)
  • Winner, the College of Law Plea in Mitigation Competition (2012)
  • Middle Temple Astbury Scholar (2011)
  • Human Rights Lawyers’ Association Bursary (2010)
  • Middle Temple Astbury Scholar (2008)
  • ‘The European Arrest Warrant and Defence Rights’, European Criminal Law Review, 2012
  • ‘The European Investigation Order: Changing the face of evidence-gathering in EU cross-border cases’, New Journal of European Criminal Law, 2011, co-author
  • ‘The European Arrest Warrant: The Role of Judges When Human Rights are at Risk’, New Journal of European Criminal Law, 2011, co author
  • Specialist Advocates’ C panellist for Health & Safety and Environmental Law

Before coming to the Bar, Daniel was the Policy Officer at the human rights NGO Fair Trials International (FTI), where he assisted in the formulation of the organisation’s policy stance on fair trial issues and helped deliver campaigns on extradition, pre-trial detention and international evidence-sharing. This work involved arguing for defence rights at meetings with the Foreign and Commonwealth Office, the Home Office and the European Parliament.

Before working at FTI, Daniel spent a year as a paralegal in the crime department of a leading firm of solicitors. Daniel worked on a range of cases from racially aggravated public order to murder. While at the firm Daniel worked extensively on a large-scale VAT fraud (a so-called MTiC fraud or “carousel” fraud), which involved the circulation of dummy orders of mobile phones around the EU.

While undertaking his legal training Daniel volunteered for the human rights organisation Liberty and represented clients on a pro bono basis at social security hearings with the Free Representation Unit. He also volunteered for the Witness Service at the Old Bailey, supporting victims of crime, their family members and witnesses.

I, Daniel Mansell, am a data controller and can be contacted at 3 Raymond Buildings, Gray’s Inn, London WC1R 5BH or by telephone on 020 7400 6400 or by email at daniel.mansell@3rblaw.com. My Data Protection Policy can be found below.

All personal data that I process is for the purposes of providing legal services, conducting conflict-checks, marketing, defending potential complaints, legal proceedings or fee disputes, keeping anti-money laundering records, training other barristers and pupils and when providing work-shadowing opportunities, and/or exercising a right to a lien. The types of data I process vary upon the nature of the legal matter in relation to which I am engaged to advise, but can include names, contact details, biographic details and ‘special category personal data’ (such as details of racial or ethnic origin, political opinions, religious or philosophical beliefs, health, sex life and criminal convictions and proceedings).

Depending upon the circumstances of the case, the legal bases upon which I process personal data are (i) the performance of a contract to which the data subject is a party or in order to take steps at the request of the data subject prior to entering into a contract, (ii) the processing is necessary to comply with legal obligations to which I am subject, or (iii) the processing is necessary for the legitimate interests set out above, except where such interests are overridden by the interests or fundamental rights and freedoms of the data subjects which require protection of personal data, in particular where the data subject is a child. When I rely on (iii) legitimate interests, my ‘Legitimate Interests Assessment’ can be found here. When I process data which has not be obtained directly from the data subject (e.g. personal data contained in evidential materials), it will have been supplied to me as part of my instructions in circumstances covered by legal professional privilege.

Depending upon the circumstances of the case, I may share the personal data with:

  1. my Chambers, which supplies professional and administrative support to my practice;
  2. Courts and other tribunals to whom documents are presented;
  3. my lay and professional clients;
  4. potential witnesses, in particular experts, and friends or family of the data subject;
  5. solicitors, barristers, pupils, mini pupils and other legal representatives;
  6. ombudsmen and regulatory authorities;
  7. current, past or prospective employers;
  8. education and examining bodies;
  9. business associates, professional advisers and trade bodies.

I retain personal data for no longer than 7 years after the case has come to an end or as otherwise required by law.

I do not intend to transfer data to any country which is not either within the European Union, ‘white listed’ by the EU or otherwise permitted by EU law (e.g. to the USA under the provisions of the ‘Privacy Shield’).

Under the GDPR, data subjects whose personal data I process have the right to request from me access to, and rectification or erasure of, their personal data, the right to the restriction of processing concerning them, the right to object to processing as well as the right to data portability. Data subjects also have the right to lodge a complaint with the Information Commissioner’s Office (ico.org.uk).

In cases where there is a contract between me and the data subject, the provision of personal data is a contractual requirement and the data subject is obliged to provide the personal data in order that I can supply legal services. A failure to provide such data may mean that I will not be able to provide the legal services.

Rev 1.0 – 24.05.2018

Data Protection Policy

Legitimate Interests Assessment

Daniel Mansell is qualified to accept instructions direct from clients under the Bar Council’s Public Access Scheme. This means that members of the public who seek specialist advice can come direct to him. In addition, he welcomes instructions from solicitors, in-house law departments, qualified foreign lawyers, and clients licensed by the Bar Council to give instructions direct to barristers under the Bar Council’s Licensed Access Scheme.

For further information please contact our Clerks.

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