PATRICK J. HARRISON advises on all aspects of EU and UK competition law. Patrick spent four years in Brussels before relocating to Sidley’s London office in 2007 and is admitted both as a Solicitor in England and Wales and as an Advocaat in Belgium. He has significant experience representing clients before the European Commission and the UK’s Competition and Markets Authority (CMA), securing favorable results for clients requiring regulatory approvals, or facing regulatory challenges.
Patrick focuses his practice on merger control, cartel and dominance investigations, counselling, and compliance. He has also represented clients in EU and UK judicial review proceedings regarding both competition cases and legislation of broader application. In this context, he has pleaded a number of cases before the EU Courts.
Patrick has received acknowledgment from numerous industry ranking guides:
- Chambers UK 2025 – Ranked for Competition Law, sources commented “What sets him apart is his ability to look at the transaction as a whole. He is very rarely acting in a vacuum and he can tailor his advice accordingly.”
- Legal 500 UK 2025 – Ranked for EU and Competition.
- Chambers Europe, Chambers Global and Chambers UK 2024 – Ranked for Competition Law, where clients noted “Patrick has been a pleasure to work with. His knowledge of antitrust material is expansive and his contributions at meetings have been highly appreciated.”
- Legal 500 UK 2024 – Ranked for EU and Competition, where sources say “Patrick Harrison is a pleasure to deal with, both professionally and personally. He works well with the clients and runs the meetings with a sure hand.”
- Chambers UK 2023 – where clients describe him as “outstanding at understanding the regulatory issues but putting them in terms that our teams can understand so that they can make appropriate strategic decisions.”
- Chambers Europe 2023 – Ranked for EU Competition Law where clients noted “his client service level” as being “extraordinary, from his responsiveness to the clarity of the counsel he provided.”
- Legal 500 UK 2023 – Ranked for EU and Competition, where he is described as “an excellent partner.”
- Chambers Europe 2022 – Ranked for Competition Law, with clients saying he is “extremely hard-working and takes the time to listen to us.”
- Chambers UK 2022 – Ranked for Competition Law, sources commented that he is an “excellent antitrust lawyer, very pragmatic and knowledgeable, and a pleasure to work with.”
- Chambers UK 2021 – Ranked for Competition Law
- Chambers UK 2020 – Ranked for Competition Law, where clients described him as “articulate, clear and very responsive.”
Patrick is the contributing editor for the Lexology Panoramic: Vertical Agreements, publication and has published widely on EU and UK competition law issues. He has also presented at a number of industry events, including events organized by the American Bar Association and the UK’s Regulatory Policy Institute.