Roger Stewart QC > Chambers of Mark Cannon QC > London, England > Lawyer Profile

Chambers of Mark Cannon QC
4 New Square

Living Wage


Has a broad commercial practice with particular specialisation in international arbitration, insurance and construction as well as professional liability; recently acted in very substantial disputes for and against sovereign states as well as in private law claims. Recent cases include: Costain Ltd & Ors v Bechtel Ltd & Anor [2005] EWHC 1018 (TCC); Beary v Pall Mall Investments [2005] EWCA Civ 415; Multiplex Construction (UK)Ltd v Cleveland Bridge UK Ltd & Anor [2007] EWCA Civ 1372; Kamar v Nightgale & Anor [2007] EWHC 2982(QB); HLB Kidsons v Lloyds Underwriters & Ors [2007] EWHC 2699; Nationwide Building Society v Dunlop Haywards Ltd & Anor [2007] EWHC 1374 (Comm); Cherney v Deripaska [2007] EWHC 965 (Comm); Mirant Asia-Pacific Construction (Hong Kong) Ltd v Ove Arup & Partners International Ltd & Anor [2007] EWHC 918(TCC); Baxendale-Walker v The Law Society [2007] EWCA Civ 233; Fulham Leisure Holdings Ltd v Nicholson Graham Jones [2008] EWCA Civ 84; Cheshire Building Society v Dunlop Haywards (DHL) Ltd & Ors [2008] EWHC 51 (Comm), Mehjoo v Harben Barker, [2014] EWCA Civ 358, Gabriel v Little, [2013] EWCA Civ 1513, Clydesdale Bank v Workman [2013] EWHC 110, Amec v MOD [2013] EWHC 110, Capita v Drivers Jonas [2012] EWCA Civ 1417, Shepherd v Pinsent Masons [2012] EWHC 43, Trigger Litigation [2012] UKSC 14, Hawksford v Stella [2012] EWCA Civ 55, Harrison v Shepherd Homes [2011] EWHC 1811; City & General v Royal & Sun Alliance [2010] EWCA Civ 911.


Qualified 1986; Inner Temple; Bencher 2002; Junior Bench Auditor; publications: general editor of 5 to 7th editions in succession to Sir Rupert Jackson of ‘Jackson and Powell on Professional Negligence’; Silk 2001; Bencher 2002.




Oundle School; Jesus College, Cambridge (1985 LLM, 1986 MA).


National Liberal Club, Lost Valley Mountaineering Association, Serpentine Swimming Club.

Lawyer Rankings

London Bar > Professional negligence

(Leading Silks) Ranked: Tier 1

Roger Stewart QC – 4 New Square ‘He has fantastic knowledge of professional negligence law, and a very good approach to strategy – very user friendly and a top choice for leading professional service firms.

4 New Square ‘is one of the go-to sets for professional negligence work‘, and is highlighted for its ‘tremendous strength in depth‘, with ‘a wide range of excellent barristers available to assist‘. The ‘approachable and user-friendly‘ set is experienced in cases involving professionals from across the spectrum. Highlights include Roger Stewart QC representing the defendant in Mayr and others v CMS Cameron McKenna, a high-value solicitors’ negligence claim, and Jamie Smith QC and Shail Patel defending a City investment firm in Various Investors v Canaccord Genuity, relating to the alleged mis-selling of film finance schemes. In addition, Clare Dixon appeared in the Court of Appeal in Matthew v Sedman, which involved a claim against accountants.

London Bar > International arbitration: counsel

(Leading Silks) Ranked: Tier 2

Roger Stewart QC – 4 New Square ‘An exceptionally good cross-examiner. He is calm, very persuasive in his oral submissions, has a good feel of the Tribunal and a very thoughtful and effective approach to tackling the most difficult issues.

4 New Squareis becoming one of the top sets for commercial international arbitration now and their expertise in public international law is making them increasingly a go-to set for investment arbitrations too‘. A healthy mix of experienced silks and juniors, several of which are former solicitors, has seen the set establish an increasingly strong presence in the market. Members regularly act together on cases, including Justin Fenwick QC and Timothy Chelmick, who represented the defendant in a major energy dispute. Roger Stewart QC and George Spalton were also involved in a significant development-related arbitration in Dubai.

London Bar > Professional disciplinary and regulatory law

(Leading Silks) Ranked: Tier 3

Roger Stewart QC4 New SquareHe has fantastic knowledge of professional negligence law, and very good approach to strategy – very user friendly and a top choice for leading professional service firms.

London Bar > IT and telecoms

(IT and telecoms (excluding regulatory) - Leading Silks) Ranked: Tier 3

Roger Stewart QC4 New SquareA dynamic counsel for complex IT disputes.

London Bar > Insurance and reinsurance

(Leading Silks) Ranked: Tier 4

Roger Stewart QC4 New SquareAlways on my shortlist when we require sheer depth of experience, technical capability and gravitas.

London Bar > Construction

(Leading Silks) Ranked: Tier 1

Roger Stewart QC4 New SquareHe’s just excellent, loved by clients, a great silk.

Middle East: The English Bar > Construction

(Leading silks) Ranked: Tier 1

Roger Stewart QC4 New Square

At 4 New Square, Roger Stewart QC is active as arbitrator (both party-appointed and chair) and counsel in disputes spanning the GCC region, often on instructions from firms in the region. Turning to the set’s juniors, Timothy Chelmick is counsel for well-known contractors on DIAC and ICC arbitrations.