Paul specialises in dispute resolution in contract law, financial law, civil commercial fraud, professional negligence, and company law.

Apart from being for many years recommended by Chambers and Partners and Legal 500, Paul is also recommended in Chambers Global rankings.

As a result of his expertise in contract law, he also undertakes commercial advisory work that has included advising a global-brand computer manufacturer on the SPA for its UK facility. He has given evidence as an expert witness on English contract law in legal proceedings in Canada and in Italy.

Until reducing his practice as the consequence of illness, the majority of his work involved claims against banks and other financial institutions for mis-sold swaps, structured derivatives and SCARPS, where he secured successful outcomes for clients against all the major UK retail banks.

He is a regular contributor to Butterworths’ Journal of International Banking and Financial Law. He has the unique distinction of having published three articles in consecutive editions of the journal: Facing the end of LIBOR: the financial and legal implications (with Hanif Virji and Arif Merali) (Dec 2019), English law of vicarious liability: off on a frolic of its own – or the flight from principle? (Jan 2020), UK Inflation indexation and the replacement of the RPI – A (pressing) conundrum (with Hanif Virji and Arif Merali) (Feb 2020).

He edited the last two editions of Atkin’s Court Forms Vol 18(1) Equitable Remedies, and previously edited Atkin’s Vol 35, Sale and Supply of Goods and Services. For several years he was on the editorial board of Butterworths Corporate Law Service.

He is widely published and frequently quoted. Recent quotations have included The Times (leading article) (25 April 2021) and the Financial Times (11 April 2022).

As a consequence of serious illness, Paul was able to devote his time to volunteering to assist, pro bono (without charge), three appellants in the Post Office appeals. The Post Office scandal has disclosed the most widespread miscarriage of justice in English legal history.

Paul, together with his junior Flora Page and his instructing solicitors Aria Grace Law, was responsible for eliciting from the Post Office the now infamous “Clarke Advice”, the most important document in the appeals (Lord Falconer is on record as describing it as the “smoking-gun”). The identification of that document was critical in the Court of Appeal’s eventual finding against the Post Office of “second category abuse of process”. It transformed the appeals and resulted in the government from June 2021 elevating the inquiry by Sir Wyn Williams to a statutory inquiry. It is the ultimate cause of the government expressing a willingness to properly compensate victims of the Post Office who were party to the massive group civil litigation between 2016-2019. Paul has lectured widely on the Post Office fiasco and has been interviewed by BBC1 (Panorama) and BBC Radio 4. Nick Wallis, author, broadcaster and journalist, described Paul’s lecture to the University of Law, in June 2021:

“Late yesterday afternoon, at the University of Law in London, the barrister Paul Marshall delivered one of the most important speeches on the Post Office Horizon Scandal to date. Mr Marshall pulls every detail of this appalling story out of the mud and connects the dots between the Post Office, Fujitsu the legal system and government. He explains why people are culpable and under what laws.”

Paul is engaged in writing books on legal aspects of the Post Office scandal and on the law of vicarious liability and corporate attribution.