Jon Holl-Allen KC

Call 1990 | Silk 2018

Jon Holl-Allen KC | Call 1990 | Silk 2018

Back to Our People


Jon has been a medical lawyer throughout his career at the Bar. In clinical negligence cases he acts for claimants and for defendants on behalf of all the major medical defence organisations and the NHSLA. A substantial part of his practice for the last 15 years has been acting on behalf of the practitioner in professional discipline cases, particularly in the medical and dental fields. He is described in the latest edition of The Legal 500 as “vastly experienced, erudite and articulate.”

Jon is clerked primarily by Lee Johnson, Clare Sabido, Jennifer Pooler and Emma Bell

“Jon is delightful to work with. He is assured, astute and always on top of the issues involved. He conveys authority and can be relied upon to be close to the detail when handling difficult, complex cases.”
Chambers & Partners

Jon acted in General Dental Council v Kirschner

 Experience & Expertise

Jon specialises in clinical negligence and healthcare, professional discipline, inquests and inquiries, police and employment law.

Jon has a complex and high value clinical negligence work load. On the defence side he has been instructed for over 20 years by all the major medical and dental defence organisations, by the NHS in Wales, and by the NHSLA since its foundation. He is also routinely instructed on behalf of claimants in high value and medically complex cases. Recommended by both the leading legal directories in this field, he is described by the current edition of the Legal 500 as a thoughtful, steady hand, who instils confidence and has good judgement.

Jon is also known for his professional discipline expertise, having been instructed in professional disciplinary cases since 1997. He has regularly appeared in the General Medical Council and General Dental Council since that time. He continues to be instructed by all of the medical and dental defence organisations in such cases. He has been instructed in a number of cases in which he has represented doctors in internal disciplinary proceedings, often against a background of actual or potential proceedings against the practitioner by his or her regulator. Again he is ranked as a leading barrister in this field by both the legal directories, with the current edition of Chambers & Partners noting that “he is very sharp, bright and takes a forensic approach, which makes him extremely good in complex clinical cases”.

He has appeared in many medical inquests. He has maintained an interest in employment law, especially in cases in which there is both an employment and a professional discipline element, and his experience of employment law extends into the police field, in which he has appeared in many discrimination cases. He has a particular and longstanding expertise in police pensions cases.

cases & work of note

Jon’s recent clinical negligence cases have included:

EPX v Milton Keynes General Hospital NHS Foundation Trust
Jon represented the Claimant who had sustained brain damage in the neonatal period due to a failure promptly to treat a Group B streptococcus infection. Liability was admitted at an early stage after issue of proceedings but quantum proved more difficult. In January 2016 however settlement was approved on favourable terms.

Willis v Stern
Jon represented the defendant GP in this case which came to trial in June 2015. The claimant alleged that the GP had negligently failed to refer him for a specialist opinion when he was presenting with what proved to be a cervical myelopathy.  This had led, on his case, to a 2-year delay in diagnosis and treatment of his condition and to his developing a grossly debilitating global pain syndrome. £1.9m was claimed.  The defendant was successful on both breach of duty and causation issues, in that the pain syndrome (although genuine) was not found to have been caused by the delay in diagnosis and treatment of the cervical myelopathy.

Jones v Abertawe Bro Morgannwg University Local Health Board
This claimant in this case had undergone emergency abdominal surgery for a suspected appendicectomy, but histology following surgery showed that she had been suffering from a diverticulitis which could have been treated by antibiotics.  The claimant alleged that a CT scan ought to have been carried out preoperatively which would have made the correct diagnosis, alternatively that she ought to have been told of the option of investigation by CT scan.  The alternative case raised a legal issue as to the application of Montgomery v Lanarkshire Health Board. Jon represented the successful defendant at trial.

Jon’s recent professional discipline caseload has included:

General Dental Council v Kirschner:
This case involved allegations inter alia of dishonest claims under the NHS dental contract. Dishonesty was found proved in part by Professional Conduct Committee of the GDC and a suspension of 12 months was imposed. The findings of dishonesty were overturned on appeal to the High Court (Mostyn J) in May 2015.  There was detailed consideration by the court of the correct legal test for dishonesty in disciplinary proceedings, of significance to all regulated professionals. The Ghosh test for dishonesty was affirmed, with reluctance, by the judge. When quashing the findings of dishonesty the judge agreed with Jon’s description of the findings of the PCC as “internally inconsistent” and “incoherent”. The case was remitted to PCC for reconsideration of sanction on other matters and a reprimand was imposed.

A Health Board v X:
These were complex disciplinary proceedings relating to a consultant surgeon. Concerns were raised about mortality rates and he was suspended amid national publicity. Jon represented him in GMC proceedings in which deficient professional performance was alleged and in complex internal disciplinary proceedings involving a detailed analysis of his management of 17 patient cases.

General Dental Council v X: 
Jon represented a dentist with a high media profile. He had performed extensive crownwork, in part for cosmetic reasons, and the treatment was unsuccessful. It was alleged that the treatment was inappropriate and that the dentist had persuaded the patient to undergo expensive treatment which he knew was not suitable for her and that he therefore was dishonest. The allegations of dishonesty were successfully defended. Although the Professional Conduct Committee were critical of the treatment provided, the dentist’s fitness to practice was found not to be impaired.

Jon has recently represented several doctors required to give evidence by deposition in England in connection with product liability proceedings ongoing in the United States.


Jon is recommended by both The Legal 500 and Chambers & Partners for clinical negligence and professional discipline and regulatory law.

Recent directory editorial has included the following:

  • his cross-examination is incisive and very effective;
  • absolutely superb;
  • he is totally unflappable under significant pressure from opponents;
  • excellent at getting to the bottom of complex issues;
  • one of the most meticulous barristers you could hope to instruct;
  • his biggest strength is his eye for detail;
  • he has exceptional advocacy and client handling skills;
  • he is incredibly thorough and never misses a thing;   
  • he has a very shrewd mind and advises on novel areas of law with confidence and enthusiasm. He is fantastic with clients, judges and panels;
  • he has an excellent grasp of detail;   
  • vastly experienced, erudite and articulate;   
  • Jonathan is calmness personified and a brilliant advocate;
  • he is very intelligent and meticulous;
  • very user-friendly and sensible;
  • careful, methodical, well prepared and I think a really classy and considered counsel;
  • a thoughtful, steady hand, who instils confidence and has good judgement;    
  • he impresses with his academic grasp of case law;
  • an absolute pleasure to work with;
  • produces penetrating and well-considered commentary;   
  • identifies issues quickly and provides advice in a direct albeit customer-friendly way;
  • an absolutely excellent advocate;
  • he is very measured and very deliberate;
  • he’s extremely experienced, knowledgeable and great with clients;
  • he is extremely methodical and logical;
  • a very good lawyer who is calm and unflappable;
  • clients are reassured by his pragmatic advice;
  • he thinks about every word he’s going to say;
  • has been extremely effective when putting forward a client’s position;    
  • he approaches cases logically, methodically and thoroughly, which means no stone is left unturned;
  • Jon is delightful to work with;
  • a very accomplished barrister and a master of detail;
  • his depth of knowledge in healthcare matters, particularly in professional discipline and regulation, is impressive;
  • he has a calm, sensible, methodical;
  • very professional approach;
  • he is very well prepared on all aspects of his case and advises effectively and comprehensively, quickly gaining the confidence of clients and solicitors alike;
  • he is assured, astute and always on top of the issues involved;
  • he is very good at being robust when he needs to be, but also at pouring oil on troubled waters;   
  • he’s incredibly nice and very thorough; 
  • perfect for guiding clients through the process;   
  • he is calm, collected and totally unflappable; 
  • he has unrivalled expertise at all levels combined with a cost-effective and practical approach;    
  • thoroughly pleasant;
  • very easy to work with;
  • extremely sure-footed;
  • very analytical;
  • straight as an arrow;
  • he pulls no punches and can gains the trust of opponents and decision-makers through his charm;
  • thorough knowledge of the authorities;
  • very knowledgeable and thorough in his approach;
  • he’s also an excellent advocate;
  •  he puts in a lot of hard work – you can trust his advice;    
  •  calm and considered approach;
  •  an excellent advocate;   
  • highly professional, very steady and adept at advising across a range of issues;     
  • readily grasps the issues at stake; 
  • conscientious, fair and even-handed;
  • is a fine courtroom performer who gets good results;
  • his calm and methodical approach lends authority to his advocacy; 
  • his judgment in presenting cases both orally and in writing is excellent;
  • can be relied upon to be close to the detail when handling difficult, complex cases; and
  • his advocacy is truly exceptional.


Jon is a Contributing Editor to the Medical Law Reports. He has reported recently on the following cases:

  • Iddon v Warner [2021] Med LR 384 Fundamental dishonesty – Clinical negligence – Dishonesty in respect of quantum of claim – Successful application by defendant for dismissal of claim on ground of dishonesty.
  • Simawi v GMC MLR 2020 36 [2020] Med LR 487 General Medical Council – Sanction – Suspension for nine months with a review following findings of dishonesty – Whether period of suspension excessive – Whether review direction an appealable decision under Medical Act 1983, section 40.
  • Paul v The Royal Wolverhampton NHS Trust [2020] EWHC 1415 (QB) [2020] Med LR 267 Clinical negligence – Secondary victims – Nervous shock – Proximity – Relevant event for purposes of establishing liability under control mechanisms – Collapse and death of deceased from heart attack at time and place remote from allegedly causative breach of duty.
  • OX v Derby Teaching Hospitals NHS Foundation Trust [2016] 9 WLUK 315 [2020] Med LR 458 Clinical negligence – Obstetric brain damage – Breach of duty in midwifery care – “Conventional model” of time frames of brain damage preferred to “extended model” in analysis of causation.
  • O’Connor v The Pennine Acute Hospitals NHS Trust [2015] EWCA Civ 1244 [2016] Med LR 11 Clinical negligence – Intraoperative damage – Sufficiency of evidence – Res ipsa loquitur – Rhesa Shipping heresy – Permission to adduce expert evidence.
  • Cambridge Uni Hospitals NHS Foundation v BF[2016] EWCOP 26 [2016] Med LR 314 Court of Protection – Mental illness – Capacity – Best interests – Life-sustaining treatment causing infertility.
  • NAT v Sec of State for Health [2016] EWHC 2005 (Admin) [2016] Med LR 487 Judicial review – Allocation of NHS budgetary responsibility – Power to commission preventative treatment – Preventative treatment for HIV/AIDS – National Health Service Act 2006, section 1H(2).
  • Border v Lewisham & Greenwich NHS Trust [2015] EWCA Civ 8 [2015] Med LR 48 Clinical negligence – Trespass to the person – Consent – Causation – Amendment of statement of case.
  • A v East Kent Hospitals NHS Found. Trust [2015] EWHC 1038 (QB) [2015] Med LR 262 Clinical negligence – Consent – Material risk – Wrongful birth – Chromosomal abnormality – Anonymity order.
  • R (Chaudhuri) v GMC [2015] EWHC 6621 (Admin)[2015] Med LR 440 General Medical Council – Time limits – Jurisdiction – Mistake of fact as to dates of events giving rise to allegation – Power to correct decisions vitiated by fundamental mistakes of fact – General Medical Council Fitness to Practise Rules 2004 (SI 2004 No 2608), rule 4(5).
  • Krebs v NHS Commissioning Board [2013] EWHC 3474 (Admin) [2014] Med LR 70 General dental practitioner – Contract – Contract for the provision of dental services under the NHS – Breach of contract – Termination of contract – Whether private and public law remedies available to dental contractor – Whether article 1 of First Protocol to ECHR engaged by termination of contract.
  • R (Blue Bio) v Secretary of State for Health [2014] EWHC 1679 (Admin) [2014] Med LR 233 Pharmaceuticals – Medicinal products – Food supplements – Meaning of “medicinal product” for the purposes of the Medicines Directive (2001/83/EC) – To what extent products containing glucosamine “medicinal products” for purposes of Directive – Whether MHRA policy in respect of such products unlawful.
  • Chakrabarty v Ipswich Hospitals NHS Trust [2014] EWHC 2735 (QB) [2014] Med LR 379 Employment – Breach of contract – Contractual disciplinary procedures – Capability – Maintaining High Professional Standards in the Modern NHS (“MHPS”) – Relationship between NCAS assessments, GMC Fitness to Practise procedures and internal disciplinary process – Injunctive relief.


When I started in chambers I did the full range of common law work – everything from crime to landlord and tenant, consumer credit to family law.  With hindsight this was an excellent foundation for the specialist work which followed, and I have always tried to retain diversity in my practice, to be adaptable in accepting instructions in areas related, but not necessarily central, to my core areas of practice, and to appreciate the overlap between those areas, such as professional discipline and employment law and the potential implications of one set of proceedings for another.

Not every area of practice provides the same opportunity for advocacy, in particular oral advocacy, but expertise in advocacy is critical in most areas of practice at one time or another, and advocacy is a skill which needs constantly to be practised. I have been heavily involved in professional discipline work for about 20 years and the regular experience of cross-examination of factual and expert witnesses in that field has been invaluable on the occasions on which such questioning has been required in clinical negligence or other trials.

I believe that the experience that I have had in acting for one side to a type of dispute has made me a better advocate when acting for the other.

One of the strengths of an independent advocate is perspective, the experience of having seen disputes from different, and often opposing, angles. A clinical negligence dispute is of the utmost importance to the injured claimant and those who care for him or her, who are likely to have much invested in it emotionally as well as financially; so too is it important to the clinician accused of causing injury by negligent care, whose confidence may be shaken to the core by a single case and who may be devastated by the suffering of the claimant. I believe that the experience that I have had in acting for one side to a type of dispute has made me a better advocate when acting for the other.

I think that the most important attribute of an advocate is clarity. Our job is to listen, analyse, assess, explain and ultimately to persuade, but you can’t persuade if you are not clear.


Jon adopts and adheres to the provisions of his privacy notice which can be accessed here.

further information

For further details of Jon’s practice please click on the links to the left or contact a member of the clerking or client service team.

Bar Council Membership No: 26371
Registered Name: Jonathan Guy Holl-Allen
VAT Registration No: 524424272