Cleon Catsambis > Chambers of Ewan McQuater KC and David Quest KC > London, England > Barrister Profile

Chambers of Ewan McQuater KC and David Quest KC
3 Verulam Buildings


Cleon has a strong and well-regarded commercial practice that encompasses commercial litigation and dispute resolution, banking & finance, financial services, regulatory & disciplinary law, company law and insolvency. He also practises in aviation and administrative and public law. He is recognised as a Leading Junior in the legal directories, which state that “he is excellent at practically applying legal concepts and rulings to a situation”.

Cleon advises and acts for individuals, firms, investors, banks and regulators on the full range of issues arising under the domestic and European/international legal framework, including compliance and enforcement, judicial review, professional negligence, mis-selling claims and collective investment schemes. In 2014, Cleon worked in-house with the Enforcement and Financial Crime Division of the Financial Conduct Authority.

He regularly appears as sole and junior counsel in high-value and complex disputes in the High Court, the Court of Appeal and a variety of Tribunals. His cases often involve an international dimension and he has substantial experience of jurisdictions in the Caribbean (including BVI, the Cayman Islands, the Bahamas, Barbados and Jamaica) as well as the Russian Federation, Cyprus and the Netherlands.

Recent notable work includes:

  • Acting for a defendant in worldwide $2 billion litigation brought by the Danish tax authority (SKAT) to recover withholding tax refunds.
  • Acting for the petitioner in a 5-day hearing of a bankruptcy petition where there underlying debt related to the financing and ownership of the ‘Financial City’ complex in Madrid (valued at c.£3 billion).
  • Acting for Cornwall Council in successfully obtaining declaratory relief that it was entitled to lawfully terminate a 10-year £160m public procurement outsourcing contract forthwith on the basis of material breach.
  • Advising a major broadband and telecommunications provider in respect of a prospective benchmarking claim valued at £100m.


Called 2011, Lincoln’s Inn (Lord Bowen Scholar, Lord Denning Scholar, Hardwick Entrance Award, Buchanan Prize)

Cleon is an editor and contributing author to several leading publications, including:

  • Butterworths Financial Regulation Service
  • Atkin’s Court Practice (Financial Services and Administrative Law volumes)
  • Jordan’s Regulatory and Disciplinary Proceedings


COMBAR, FSLA, Bar Pro Bono Unit


Bar Professional Training Course (Outstanding, 2nd in year), BPP Law School (2011)

Graduate Diploma in Law (Distinction), BPP Law School (2010)

MSc Global Governance & Diplomacy (Distinction, 1st in year), University of Oxford (2007)

BSc Government & History (First Class Honours), London  School of Economics (2006)

Lawyer Rankings

London Bar > Aviation

(Leading Juniors)Ranked: Tier 4

Cleon Catsambis3 Verulam Buildings ‘He is an excellent barrister and has interpersonal skills as well as being a hard worker.’

London Bar > Art and cultural property

(Leading Juniors)Ranked: Tier 1

Cleon Catsambis3 Verulam Buildings

London Bar > Financial services regulation

(Leading Juniors)Ranked: Tier 3

Cleon Catsambis3 Verulam Buildings ‘Cleon has great experience in financial services law and is trusted by clients and the court alike.’

London Bar > Banking and finance (including consumer credit)

(Leading Juniors)Ranked: Tier 3

Cleon Catsambis3 Verulam Buildings ‘Cleon is a diligent barrister and develops a great control over documents and facts in a case such that he is an asset to any legal team. He is a great asset to the team.’