Jonathan Clark > Slaughter and May > London, England > Lawyer Profile

Slaughter and May

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Jonathan is a Partner with a strong and varied litigation and investigations practice advising a wide range of financial services and corporate clients. He has deep experience defending allegations of deliberate wrongdoing, having advised on criminal and regulatory investigations and litigation involving alleged corruption, fraud, cartel activity and tax evasion.

Jonathan’s litigation practice includes a focus on banking cases relating to complex derivatives transactions and benchmark manipulation, as well as multi-jurisdictional competition litigation in a number of sectors. He also advises clients in a number of different industries on appeals to the Competition Appeals Tribunal from decisions of the UK competition authorities.

Jonathan has particular interest and experience in advising clients in relation to ongoing business and PR issues in the context of live litigation or investigations.


Trained Bell Gully; qualified 2004 (New Zealand), 2008 (England and Wales); joined Slaughter and May 2007; partner 2014.

Lawyer Rankings

London > Dispute resolution > International arbitration

Slaughter and May‘s ‘absolutely stellar practice‘ acts in major disputes for clients from the energy, infrastructure, healthcare and pharmaceuticals sectors (among others). The international arbitration group is co-led by James Stacey, who is well known for challenging commercial disputes, and ‘visionary arbitration partnerDamian Taylor. The team additionally fields energy disputes specialist Efstathios Michael and Jonathan Clark, who acts under the rules of major arbitral institutions. Peter Wickham and Megan Sandler were elevated to the partnership in 2021 and 2022, respectively.

London > Corporate and commercial > Financial services: contentious

(Next Generation Partners)

Jonathan ClarkSlaughter and May

At Slaughter and May, the practice is able to leverage the experience of Deborah Finkler, a lawyer with a three-decade long track record of acting on FCA, PRA and FOS proceedings. Elsewhere, Ewan Brown serves as a go-to within the market for FX manipulation cases, while Holly Ware is a figure of prominence owing to her LIBOR investigation, market abuse and money laundering know-how. Jonathan Cotton is acclaimed for his capabilities in export controls and sanctions, Company Act offences and FSMA matters, among many others, and the team also includes Gayathri Kamalanathan, an up-and-coming partner with over 10 years experience of senior in-house roles at leading banks. Jonathan Clark is also a key name to note. Richard Swallow leads the group.

London > Dispute resolution > Banking litigation: investment and retail

(Leading individuals)

Jonathan ClarkSlaughter and May

Slaughter and May‘s banking litigation team offers ‘strength in depth at all levels’. The overall disputes and investigations group is led by Richard Swallow, while key figures in litigation include Ewan Brown, who has experience advising in relation to corporate crime, competition claims and tax appeals, and Camilla Sanger, whose practice covers commercial, banking and competition litigation. Both are described by one client as ‘perfect performers as partners’. ‘Hugely experienced‘ Deborah Finkler, and Jonathan Clark, who specialises in defending against allegations of deliberate wrongdoing, are also key part of the banking litigation team, which works across the financial services sector for high profile clients including JPMorgan Chase, Deutsche Bank and Credit Suisse. The practice has been in growth mode,  with Gayathri Kamalanathan joining as a partner in April 2021 from Danske Bank in Copenhagen, where she was head of group litigation and enforcement.   Peter Wickham  was made up to partner the same year.

London > Dispute resolution > Competition litigation

Fielding a pre-eminent competition litigation practice, Slaughter and May regularly acts on some of the largest private enforcement actions before the UK Competition Appeal Tribunal and High Court, as well as appeals before both national courts and the CJEU. Pooling cross-disciplinary expertise, the firm is praised for its ‘sheer quality’. Disputes and investigations practice head Richard Swallow has extensive experience of multi-jurisdictional competition litigation, having advised high-profile global clients such as Volkswagen and JPMorgan Chase. The team also benefits from ‘brilliant tactician’ Damian Taylor and ‘excellent litigator’ Jonathan ClarkCamilla Sanger, who has built up a large contentious antitrust practice, is also recommended along with ‘formidable strategistHolly Ware and Elizabeth Jordan.