Jack Williams > Chambers of Tim Ward KC and Philip Moser KC > London, England > Lawyer Profile

Chambers of Tim Ward KC and Philip Moser KC
Monckton Chambers

Work Department

Competition law, Procurement law, Public law, EU law, Sports law, Commercial law


Jack practises in Competition Law; Public Procurement Law; Administrative & Public Law; and EU & EU Relations Law. He has been instructed in significant litigation at all judicial levels in the UK and EU:

  • Competition Law: Jack’s clients include: Google (in four separate matters), Intas Pharmaceuticals, Intel, the International Tin Association, the CMA, the FCA, and Samsung. He has extensive experience of collective proceedings on both sides, having acted in Gibson v Pride [2017] CAT 9 (respondent); Le Patourel v BT Group (applicant); and Coll v Google (respondent).
  • Procurement Law: Jack’s clients include: Arriva, CAF, Eurotunnel, HMRC, Medequip, Merseytravel, the Ministry of Defence, and the Ministry of Justice.
  • Administrative & Public Law: Jack acted in Miller v Secretary of State for Exiting the European Union [2017] UKSC 5. He is co-editor (with Professors Mark Elliott and Alison Young) of a collection entitled: “The UK Constitution after Miller: Brexit and Beyond”. Before becoming a Barrister, Jack was a College Lecturer at Brasenose College (University of Oxford) where he taught Administrative Law and Constitutional Law.
  • EU Law & EU Relations Law: As a member of the Irish Bar, Jack retains privilege to advise on matters of EU law and his rights of audience before EU Courts. Jack has been at the forefront of legal matters arising out of Brexit and the UK’s new relationship with Europe – EU Relations Law. He is the founder and editor of www.eurelationslaw.com. He has represented clients at the CJEU in Luxembourg in numerous matters, and was a stagiaire to the last UK Judge at the CJEU before becoming a Barrister.

Jack is a member of the Attorney General’s C Panel. In addition to England and Wales, Jack is called to the Bars of Ireland and Northern Ireland. He is a graduate from the University of Oxford (Hertford College) with a Distinction in the BCL Masters in Law (ranked 2nd in the year). Before that, he graduated from the University of Cambridge (St Catharine’s College) with a First Class Degree in Law. Jack was the recipient of Gray’s Inn’s top scholarships for Bar School and Pupillage.


Called 2015.



  • Blackstone’s Guide to the Internal Market Act 2020 (A. Bates, G. Peretz Q.C., B. McGurk and J. Williams (OUP, 2021)
  • The UK Constitution after Miller: Brexit and Beyond (M Elliott, J Williams and A Young eds) (Hart, 2018) (available here)


  • “The Miller tale: an introduction” in The UK Constitution after Miller: Brexit and Beyond (M Elliott, J Williams and A Young eds) (Hart, 2018)
  • “Prerogative Powers After Miller: An Analysis in Four E’s” in The UK Constitution after Miller: Brexit and Beyond (M Elliott, J Williams and A Young eds) (Hart, 2018)
  • “Proportionality in English Administrative Law” in The Judge and the Proportionate Use of Discretion: A Comparative Administrative Law Study (Sofia Ranchordás and Boudewijn de Waard eds) (Routledge, 2015)


  • “A priceless victory for consumers: the Court of Appeal revitalises competition law’s collective actions: Merricks v Mastercard [2019] EWCA Civ 674” (2019) 38(3) Civil Justice Quarterly, 327-337
  • “Some things money cannot buy – lessons learned from the latest judgment under the UK’s new regime for collective competition law claims: Merricks v Mastercard Inc” (2018) 37(1) Civil Justice Quarterly 48-61
  • “Brexit and EU Sports Law” Global Sports and Taxation Reports (No 1, March 2017)
  • “The protean principle of proportionality: how different is proportionality in EU contexts?”, (2016) 75(2) Cambridge Law Journal 186
  • “‘Well, that’s a relief (from sanctions)!’ —Time to Pause and Take Stock of CPR r.3.9 Developments within a General Theory of Case Management”, (2014) 33(4) Civil Justice Quarterly 394

Blog posts


Jack is a member of the Attorney General’s C Panel.


MA(Cantab)  – First Class UndergrComaduate Degree in Law
BCL (Oxon) – Distinction Masters Degree in Law

Awards and prizes

Bar Professional Training Course: BPP & Gray’s Inn

  • Arden Scholarship (Gray’s Inn), 2015
  • Bedingfield Scholarship (Gray’s Inn), 2014
  • Residential Scholarship (Gray’s Inn), 2014
  • Excellence Award (BPP), 2014

Postgraduate: Oxford University, 2014

  • Vinerian Proxime Accessit Scholarship, 2014 (for coming overall 2nd in the year)
  • The University’s Prize for Comparative Public Law, 2014 (for coming top in the year)

Undergraduate: Cambridge University

  • The University’s ‘Littleton Chambers Prize for Labour Law’, 2012 (for coming top in the year)
  • The University’s ‘E.C.S Wade Prize for Administrative Law’, 2011 (for coming top in the year)
  • Ms Payne (1610) Scholarship, 2012
  • The College’s ‘Adderley Prize for Law’, 2012
  • The College’s ‘Lauterpacht Prize for International Law’, 2011
  • The College’s ‘Simmons and Simmons Prize for Constitutional Law’, 2010
  • Gooderson Memorial Scholarship, 2013

Lawyer Rankings

London Bar > Competition

(Rising stars)Ranked: Tier 1

Jack WilliamsMonckton ChambersHighly intelligent and articulate, Jack is able to get to grips with complex issues and deal with a high volume of work; no doubt a future silk in the making.

London Bar > Public procurement

(Rising stars)Ranked: Tier 1

Jack WilliamsMonckton Chambers