Claire is Head of the Competition Group globally and works in Slaughter and May’s Brussels and London offices.

Claire has extensive experience of both EU and UK competition law. She has been involved in a large number of high-profile merger cases before the EU and UK 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:

Vodafone on its proposed merger with Three UK and its acquisition of parts of Liberty Global
Activision on its acquisition by Microsoft
Suez on the public takeover bid by Veolia
Facebook on its acquisition of Kustomer
INEOS on its acquisition of TotalEnergies’ 50% interest in three joint venture chemical production businesses
Google in relation to the European Commission’s antitrust investigation into its AdSense for Search advertising services, including its successful appeal of the decision to the General Court
Motorola Solutions on its appeal of the CMA’s decision in its market investigation into mobile radio network services
Claire is recognised as a Band 1 leading individual by Chambers, a Hall of Fame leading individual by Legal 500, and a Global Elite Thought Leader by Lexology Index: Competition 2025. Claire has been named in W@Competition’s list of ‘40 in their 40s Notable Women Competition Professionals’, The Lawyer's Hot 100 list and Global Competition Review's Women in Antitrust survey. She was awarded ‘Lawyer of the Year’ in the 2025 Global Competition Review awards and 'Dealmaker of the Year' in the 2017 and 2022 Global Competition Review awards.

She is a member of the Brussels Bar (A list), as well as being qualified as a solicitor (England and Wales).

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