Willkie Farr & Gallagher (UK) LLP’s London-based competition litigation practice has established itself as a premier player, particularly noted for its strength acting for both claimants and defendants, as well as its leading collective action expertise. In February 2025, the team secured approval from the CAT for a £200 million settlement in the Mastercard v Merricks claim, marking the largest collective litigation settlement in UK history. Practice head Boris Bronfentrinker is renowned for representing claimants and defendants in high-profile cases before the High Court and CAT. Elaine Whiteford’s active practice focuses on follow-on damages litigation, regulatory challenges, and cartel investigations. Michelle Clark brings strategic insight into multijurisdictional competition litigation.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
- 'Oliwia Siutkowska: one to watch, very smart and pragmatic, great responsiveness, well structured, focused and hands-on mentality, also very strategic and fun to work with.'
- 'Elaine Whiteford: very smart, excellent strategic thinker as well, very pragmatic and down to earth, fun and easy to work with, well aware of client needs, and great overview of ongoing matters. great responsiveness.'
- 'Boris Bronfentrinker: excellent strategic thinker (very tactical as well), well aware of what a client needs, very hands-on and pragmatic approach to complex legal matters, sees the bigger picture of a case. Great responsiveness. Straightforward. Top range.'
- 'A great team of outstanding experts. They all have a deep knowledge of the relevant legal aspects, great experience before the different English courts, both on the active and the passive side, and they lead a case in a very pragmatic and strategic way.'
- ‘Top-level expertise with excellent service delivery.'
- ‘Boris Bronfentrinker and Elaine Whiteford bring deep expertise and experience in the still-evolving competition and collective action regime in the UK. They have been involved in so many of the important cases, and it shows in their strategic thinking.'
Key clients
- Which?
- The British Independent Retailers Association
- Walter Merricks CBE
Work highlights
Advised Walter Merricks during Merricks v Mastercard, the first opt-out collective proceeding certified under the UK’s 2015 Consumer Rights Act.
Instructed by the UK’s leading consumer association, Which? to bring collective proceedings against Apple on behalf of a class of consumers seeking approximately £3 billion damages.
Instructed by the British Independent Retailers Association to bring an opt-out collective action against Amazon on behalf of third-party sellers using Amazon Marketplace.
Lawyers
Leading partners
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Next Generation Partners
Junior partners with significant recognition from clients and peers in the market and key roles on multiple matters.
Practice head
Boris Bronfentrinker
Other key lawyers
Elaine Whiteford; Nicola Chesaites; Michelle Clark; Oliwia Siutkowska