Claire Jeffs

Partner, Slaughter and May

Claire is a partner at Slaughter and May and works in the firm’s Brussels and London offices. She was educated at Cambridge and Brussels universities and has been involved in a large number of high-profile merger cases before the UK and EU competition authorities, as well as coordinating merger approvals worldwide. On the contentious side, she has been involved in many cartel and other behavioural cases, including on appeal to the General Court in Luxembourg. Highlights include advising Suez on the public takeover bid by Veolia; Facebook on its proposed acquisition of Kustomer; and Google in relation to the European Commission’s antitrust investigation into its AdSense for Search advertising services and its appeal to the General Court against the Commission’s decision.

She has been named in [email protected]’s list of ‘40 in their 40s Notable Women Competition Professionals’ and The Lawyer’s Hot 100 list. Claire was awarded ‘Dealmaker of the Year’ by Global Competition Review in 2017 and 2022, and shortlisted in the ‘Lawyer of the Year’ category in the 2019 Global Competition Review awards.

She is listed as a ‘Leading Individual’ by Chambers and The Legal 500, and recognised as a ‘Thought Leader’ in Who’s Who Legal: Competition.

Claire is fluent in French and Russian and speaks good German.