Ranked in the directories as a leading junior in the Court of Protection, Oliver is regularly instructed by the full range of parties: local authorities, NHS bodies, the Official Solicitor and other litigation friends, and family members. 

Oliver accepts instructions in complex cases involving matters such as serious medical treatment, deprivation of liberty, contact, internet, sexual relations, or international protection. He is adept in cases involving learning disability and autism. His solution-oriented and calm approach is especially suited to cases where the disabled person has been labelled 'complex' and cases where relationships between the family and public bodies has broken down. 

He has a special interest in coercive and controlling behaviour in the Court of Protection and under the inherent jurisdiction of the High Court. He has a growing practice in civil committals and has recently appeared in the Court of Appeal on an appeal against a committal. 

Oliver accepts family law cases that touch on disability. He has acted for a range of parties in the Family Division, in cases concerning medical treatment, children deprived of their liberty, and secure accommodation orders.

Oliver has a niche practice representing people with learning disabilities and/or autism who have been detained for long periods under the Mental Health Act. His law reform ideas in this blog were cited during the second reading of the Mental Health Bill in the House of Lords on 25 November 2024. Oliver practices in the five areas of law that are used in combination to ensure detained patients are safely discharged into the community with a package of care: mental capacity law, mental health law, community care law, public law, and civil claims including Human Rights Act claims. These cases are often multi-year and involve several experts. An instructing solicitor in one of these cases said that Oliver had been, “fab and extremely attentive and mindful of the client.”

He accepts instructions in relation to the Mental Health Act 1983, including applications by detained patients in high secure hospitals to the First-tier Tribunal (Mental Health), appeals to the Upper Tribunal, and applications to displace nearest relatives. 

Oliver has extensive experience of strategic litigation, having spearheaded a series of successful disability rights test cases in the European Court of Human Rights from countries in central and eastern Europe, including Shtukaturov v. Russia (2008) and Stanev v. Bulgaria (2012), both cited by the UK Supreme Court.

He is Co-Chair of the national charity Respond, which provides psychotherapy to autistic people and people with learning disabilities who have experienced trauma. 

He is Consultant Editor for Halsbury Law’s “Mental Health and Capacity” with Leonie Hirst and Danielle Waddoup (2021).  

Oliver’s recent cases include:

• Re Baby Z [2025] EWHC 2100 (Fam) – Ten-month old Baby Z had neurological, cardiac and gastroenterological conditions. The two treating consultants, and four second-opinion consultants agreed that life-sustaining treatment was futile. The court decided it was in the baby’s best interests for the treatment to be withdrawn. Oliver led Asma Nizami and represented Baby Z’s parents.

• Re Patricia [2025] EWCOP 30 (T3) – Oliver represented the successful applicant family of Patricia, a 25-year-old woman with anorexia who had a very low weight. A previous judge in 2023 decided it was contrary to Patricia’s best interests to receive nasogastric feeding against her will. Arbuthnot J decided to reverse that decision, so Patricia can now be transferred to a specialist eating disorder unit for treatment. Oliver was directly instructed and worked over 150 hours on the case on a pro bono basis. Case management decision reported as [2025] EWCOP 29 (T3). Press release here.

• Cwm Taf Morgannwg Health Board v AB & Anor [2025] EWCOP 24 (T3) – Oliver represented an acute NHS Trust in this eating disorder case, where the judge made comments on the need for public bodies to focus on P by coordinating care and working across organisational silos.

• Re CA [2025] EWCOP 15 (T3) – Oliver represented the local authority in this committal which resulted in the contemnor being fined. Celia Kitzinger of the Open Justice Court of Protection Project made an application to vary the transparency order to name the contemnor, and the judgment of the media application is reported here: [2025] EWCOP 16 (T3).

• Lioubov MacPherson v Sunderland City Council [2024] EWCA Civ 1579 – Leading Beth Grossman in the Court of Appeal, Oliver represented the appellant in an appeal against a committal to prison for civil contempt. The Court of Appeal found reason to believe that the appellant lacked capacity to conduct the appeal, and sent the matter back to the Court of Protection where Theis J determined the appellant had capacity: [2025] EWCOP 18.

• Re CA (Fact Finding - Capacity - Inherent Jurisdiction - Injunctive Relief) [2024] EWCOP 64. Oliver represented the local authority in this complex CoP and inherent jurisdiction case before Arbuthnot J. 
   
• University Hospitals Bristol and Weston NHS Foundation Trust v The Mother of G [2024] EWHC 1288 (Fam), Oliver represented the applicant Trust, in which Peel J provided guidance on applications for a declaration of death. 
   
• Re ZZ (Capacity) [2023] EWCOP 61 and on appeal led by Sophia Roper KC before Theis J  at [2024] EWCOP 21 Oliver represented P in a complex capacity case concerning ADHD, impulse and sexual relations.
   
• Sunderland City Council v Lioubov Macpherson [2023] EWCOP 3: Oliver represented the defendant in a committal hearing for contempt of court before Poole J. 
   
• An ICB v (1) RN (by her ALR) and (2) TN [2022] EWCOP 41: Oliver represented P in a Covid vaccination case in which there was a subsequent appeal before Hayden J at [2022] EWCOP 53.
   
• PH & RH v (1) Brighton and Hove City Council (2) Tony Hickmott by his litigation friend, the Official Solicitor) & Ors, HHJ Hilder in London. On a pro bono basis, Oliver represented the applicant parents who of Tony Hickmott, who has spent 21 years detained in a hospital under the Mental Health Act. The Senior Judge of the Court of Protection oversaw a prolonged four-year discharge planning process. The BBC and Sky made an application to lift the reporting restriction, which was granted: PH & Anor v Brighton And Hove City Council [2021] EWCOP 63. News item here. 
   
• DP v LB Hillingdon [2020] EWCOP 45, Hayden J: Led by Victoria Butler-Cole KC, Oliver acted for P in this case which clarified the court’s approach to interim declarations under s.48 in respect of s.21A Mental Capacity Act applications. This was the first reported case brought by an Accredited Legal Representative.
   
• QJ v A Local authority & Anor [2020] EWCOP 3 and [2020] EWCOP 7: Oliver represented the litigation friend of an 87-year-old man with dementia who had been interviewed by police in relation to historic child sex offences and had then stopped eating in his care home. Hayden J found that QJ had capacity to make decisions about nutrition and hydration. Press report here.
   
• JS v South London and Maudsley NHS Foundation Trust and the Secretary of State for Justice [2019] UKUT 172 (AAC), [2020] AACR 1: Oliver represented the appellant in the Upper Tribunal, clarifying the circumstances in which the Mental Health Tribunal should accept a reinstatement of a patient's previously withdrawn application.
   
• CB (by her litigation friend, the Official Solicitor) v Medway Borough Council and Anor (Appeal) [2019] EWCOP 5: Oliver represented P, a 91-year-old woman who was deprived of her liberty in a care home. In this unusual appeal, Hayden J held that the Court of Protection should never summarily dismiss section 21(a) applications.

Oliver accepts instructions in inquests that touch on healthcare, social care or disability. He represents bereaved families, NHS Trusts and other interested persons and has appeared in high-profile inquests that have criminal, regulatory and media aspects. He is an experienced jury advocate and has appeared in many Article 2 inquests. He is also experienced in challenging Coronial decisions by way of judicial review. In the Covid Inquiry, Oliver represented the Covid-19 Bereaved Families for Justice in Module 3 (healthcare).

“Oliver has a strength in understanding healthcare-related inquests.”—Chambers and Partners, 2025

Recent cases include:

• Inquest into the death of Marcus Hanlin, Avon, April 2024. Left unattended, Marcus inhaled uncooked rice and swallowed two conkers in a care home run by the Brandon Trust. Conclusion of accident contributed to by neglect. News item here. 
   
• Inquest into the death of Matthew Caseby, Birmingham, April 2022. Article 2 with a jury. Narrative conclusion critical of the Priory Woodbourne Hospital whose neglect contributed to Matthew's death. Prevention of Future Deaths reports were issued to the Secretary of State for Health and Social Care and the Priory Group. News item here.
   
• Inquest into death of Aaron Clamp, Reading Coroner's Court, Article 2 with a jury, February 2022: Narrative conclusion that Aaron died while on 1-to-1 observation in long-term segregation in Broadmoor Hospital and that there was "a serious failure in the timely manner to recognise and reduce the level of risk and a serious failure to recognise and execute the steps" to reduce the risk. News item here.  
   
• Inquest into death of Manon Jones, Pontipridd Coroner's Court, January 2022: Critical narrative conclusion in an Article 2 case that 16-year-old Manon Jones died in a Child and Adolescent Mental Health Services (CAMHS) unit on 15-minute observations when she "ought to have been on 1:1 observation levels pending a further assessment”. News item here.

At the international level, Oliver oversaw a third party intervention in Centre for Legal Resources v. Romania (2014), a case brought by a Romanian NGO in the European Court of Human Rights. This is a leading case on the right to life under Article 2 of the European Convention on Human Rights and access to justice for people with mental disabilities. The Court found that an NGO could pursue an application on behalf of a man who died in a psychiatric hospital and had no next of kin. 

Oliver regularly advises on health and social care provision and accepts instructions in clinical negligence cases across the range of medical specialisms. 

His niche practice is in relation to Human Rights Act and negligence claims about the care and treatment of people with mental health issues, learning disabilities, and/or autism in schools, prisons, psychiatric hospitals, care homes, and the community. Recent cases include: 

Re MJ – HRA claim on behalf of three family members who developed PTSD following the death of a teenage girl who died by suicide in a CAMHS unit. 

Re AP – Led by Jamie Burton KC, Oliver represented the family of AP, a man who was detained in a seclusion suite for 340 days. The case settled. Press release here.

Re Jamie Newcombe – Oliver represented an autistic man who was detained under the MHA by a private hospital. There, staff broke his arm using an inappropriate restraint, and mis-medicated him, and as a result, Jamie developed PTSD. The case settled. Press release here. 

Re JW – Oliver represented a woman with learning disabilities who was raped by a man in a care home, as the care home owner and the local authority failed to risk assess the man. The case settled.

Oliver has conducted confidential independent investigations for health and social care entities. Supplementing his legal training, Oliver has a Master of Public Administration (MPA) and draws on more than a decade of experience as a charity CEO and his experience as a trustee, background that provides an understanding of governance, human resources, communications, and management problems in organisations.

Complementing these civil claims and investigations, Oliver draws on his experience of medical treatment cases in the Court of Protection and the Family Division. He has a healthcare-related inquest practice. He sits as a Chair of Independent Review Panels for NHS England in relation to NHS Continuing Healthcare. 

Oliver is regularly instructed to advise on judicial reviews, including those related to provision of healthcare and in respect of the Mental Health Act 1983, the Care Act 2014 and the Equality Act 2010.

Oliver has worked in international disability and mental health law and policy since 2001 and is recognised as a leading expert. He has particular expertise with the UN Convention on the Rights of Persons with Disabilities (CRPD), having participated in its negotiation in 2006. Oliver has carried out human rights monitoring and delivered training in over twenty countries in Europe, Africa, Asia, and Latin America. 

Oliver accepts instructions for advisory work, research, training, and representation on all matters of disability and mental health law. His clients have included governments, the judiciary, NGOs, philanthropic organisations, corporations, and UN bodies.

Oliver has litigated, trained, and written about children’s rights, mental health law, monitoring closed institutions (psychiatric hospitals, social care institutions, children’s homes), equality and non-discrimination, community living, guardianship and legal capacity, political participation, and access to justice. He has a particular interest in preventing and litigating ill-treatment, including sexual violence, psychiatric coercion, and conditions of detention. 

In 2021, Oliver was the lead author on the United Nations Development Programme (UNDP) report Political Participation of Persons with Intellectual or Psychosocial Disabilities. In 2022, he trained judges in Georgia on disability law, and he was one of five global experts appointed to assess CRPD implementation in Taiwan. In 2023, he wrote a report on children with disabilities for UNICEF Viet Nam and a report about deaf drivers for UNDP Georgia. His ongoing work includes supporting the judiciary in Taiwan to develop a mental health tribunal system. He is on UNDP's panel of experts on mental healthcare.

After finishing pupillage in 2001, Oliver was appointed Legal Director of the international legal advocacy NGO Validity (formerly the Mental Disability Advocacy Centre, or MDAC), and in 2006 became its Executive Director, a position he held until 2017 when he returned to the UK Bar. 

In 2006, he co-authored the book Mental Disability and the European Convention on Human Rights. As one of the drafters of the CRPD, he has written extensively on its implementation, including: 

• “Supranational Human Rights Bodies and Protecting the Rights of People With Disabilities in the COVID-19 Pandemic” in the European Human Rights Law Review in 2020; 
   
• with Soumitra Pathare, “Chronic illness, disability and mental health” in Foundations of Global Health and Human Rights, edited by Benjamin Meier and Lawrence Gostin, OUP 2020; and 
   
• with Genevra Richardson, "The right to live independently and be included in the community", International Journal of Law and Psychiatry, Vol 69, March-April 2020.

At MDAC, Oliver oversaw the world’s largest multi-country docket of disability rights test cases. Under his leadership, MDAC represented applicants or acted as amicus curiae in around 15 cases before the European Court of Human Rights, as well as numerous cases in constitutional courts and other domestic proceedings, including in Bulgaria, the Czech Republic, Russia, and Slovakia.  

Oliver has advocated before several human rights bodies, including the UN Human Rights Committee, the UN Committee against Torture, the UN Subcommittee for the Prevention of Torture, the UN Committee on the Rights of the Child, and the UN Committee on the Rights of Persons with Disabilities. He has advised UN Special Rapporteurs, and he has worked on projects with the UN Office of the High Commissioner for Human Rights (OHCHR), UNDP, UNICEF, and the WHO. In Europe, Oliver has conducted advocacy at the European Commission, the European Parliament, the Council of Europe’s Parliamentary Assembly, the Committee for the Prevention of Torture, and the Commissioner for Human Rights. In 2011, he led a successful international campaign that resulted in the Venice Commission reversing its previous recommendation that governments deny people under guardianship the right to vote.

For a full list of Oliver’s publications, see ResearchGate. Oliver blogs here. Recent publications include:

Oliver Lewis (2020) “Supranational Human Rights Bodies and Protecting the Rights of People With Disabilities in the COVID-19 Pandemic”, European Human Rights Law Review, September

Oliver Lewis and Soumitra Pathare (2020) “Chronic illness, disability and mental health” in Foundations of Global Health and Human Rights, Benjamin Meier and Lawrence Gostin (eds), OUP

Oliver Lewis and Genevra Richardson (2020) The right to live independently and be included in the community, International Journal of Law and Psychiatry, Vol 69, March-April 2020

Oliver Lewis (2018) “Council of Europe” in Lisa Waddington and Anna Lawson (eds) The UN Convention on the Rights of Persons with Disabilities in Practice, OUP

Ann Campbell and Oliver Lewis, “Violence and abuse against people with disabilities: A comparison of the approaches of the European Court of Human Rights and the United Nations Committee on the Rights of Persons with Disabilities”, International Journal of Law and Psychiatry, Volume 53, July–August 2017, Pages 45-58

Felicity Callard and Oliver Lewis (2017) “The World Psychiatric Association’s “Bill of Rights”: A curious contribution to human rights”, International Journal of Mental Health, 46:3, 157-167