Oliver is a barrister at Doughty Street Chambers, London. He practises in the field of public law, Court of Protection, inquests and international human rights law. He provides legal advice and representation to people with learning disabilities, autism and/or mental health issues and their families, as well as public bodies. He is part-time Professor of Law and Social Justice at the University of Leeds where he teaches disability law and international human rights law. From 2006 to 2017 he was CEO of Validity (formerly the Mental Disability Advocacy Centre), a human rights NGO based in Budapest that advances the rights of people with learning disabilities and/or mental health issues across the world.