LAWYER PROFILE

Claire Jeffs

UK 2026

Slaughter and May

Ranked in 1 practice area

Competition Law

London (Firms)

11 years ranked

About

Provided by Slaughter and May

Practice Areas

Competition

Global Investigations

Media & Telecoms

Career

Claire is Co-Chair 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.

Chambers Review

Provided by Chambers

Chambers Guide to the Legal Profession

Competition Law - London (Firms)

Band 1

Individual Editorial

Claire Jeffs has a strong reputation for acting on high-profile merger clearance investigations before the CMA, assisting clients from the automotive, technology and telecommunications sectors. She co-chairs the firm's competition group and offers additional experience in appeals against competition law decisions before the General Court of the European Union.

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Strengths

Provided by Chambers

Claire Jeffs might be the best merger lawyer in the country. She is an outstanding technical lawyer who has hunger and ambition. She is driven and relentless and clients get a fantastic service.
Competition LawChambers Guide to the Legal Profession
Claire Jeffs provides excellent advice with a practical approach. She is trusted by those in her field.
Competition LawChambers Guide to the Legal Profession
Claire Jeffs has provided us with her great expertise. Her experience in complex matters and leading a team shows, as well as her responsiveness.
Competition LawChambers Guide to the Legal Profession
Claire Jeffs is an excellent lawyer on big merger transactions. She builds strong client relationships and helps navigate them through the regulatory process.
Competition LawChambers Guide to the Legal Profession