Sean Brannigan KC > 4 Pump Court (Sean Brannigan KC and Rachel Ansell KC) > London, England > Lawyer Profile

4 Pump Court (Sean Brannigan KC and Rachel Ansell KC)
4 Pump Court


Joint head of chambers, Sean specialises in high-value domestic construction cases and major international arbitrations seated worldwide.Sean is regularly instructed in the UK, Middle East, Far East, Africa and North America. 

Sean’s practice is also broadly based in civil and commercial matters, specialising in professional negligence, including accountants and solicitors, building/civil engineering disputes, and landlord and tenant; has particular experience of work involving allegations of commercial fraud, and of alternative dispute resolution procedures such as mediation and adjudication.


Qualified 1994, Gray’s Inn. Silk 2009.






BA (Oxon) Law.


Cinema, socialising.

Lawyer Rankings

London Bar > Construction

(Leading Silks)Ranked: Tier 1

Sean Brannigan KC4 Pump Court ‘Sean combines a sharp intellect with practical insight. His willingness to form part of the solicitor client team means total integration into the case and in turn confidence from the client, and his advocacy is incisive and penetrating without ever being disrespectful.’

4 Pump Court offers a ‘breadth of expertise’ in construction and engineering disputes, with its barristers acting on a wide range of significant construction litigation matters both domestically and internationally. Fiona Sinclair KC is leading for Rydon Construction Ltd in London Borough of Camden v Rydon, the largest civil case to follow the Grenfell Fire regarding a dispute about cladding on five London tower blocks, acting on the design and build contractor, which also worked on the Grenfell Tower project, as defendants. Across chambers, members are also involved in other high-profile cladding claims, with five silks acting for various core participants in the Grenfell Tower Inquiry. Rachel Ansell KC is involved in Prudential and Pets at Home v Halcrow Group Limited, defending the monitoring engineer, Halcrow, concerning settlement of a warehouse floor. Sean Brannigan KC is leading on Northumbria Healthcare NHS Trust v Balfour Beatty, acting for the claimant in the PFI dispute concerning defects at the hospital, as well as having a notable international practice. Duncan McCall KC has retired.

London Bar > Energy

(Leading Silks)Ranked: Tier 1

Sean Brannigan KC4 Pump Court ‘Very thorough and user-friendly, he knows exactly what needs to be done and gives robust and solution-focused advice.’

4 Pump Court is ‘user-friendly and unpretentious, with a strong energy team, especially for upstream work and in the offshore arena’. The set has ‘a high reputation in this area and has lots of members with wide expertise’. It has particularly strong expertise in energy infrastructure matters, drawing on vast experience in related areas such as construction and engineering, shipping, insurance and professional negligence. Its members, among them standout silk Sean Brannigan KC, act for energy companies, engineers, funders, governments, operators and sub-contractors in an advisory capacity and as advocates in all forms of dispute resolution in the UK and internationally. Brannigan represented a large construction management firm in claims and counterclaims with a value in excess of $650m arising from the design and construction of the world’s largest single-phase petrochemical plant in the Middle East. Prominent silk Sean O’Sullivan KC handled the hard fought dispute BP v Galtrade, concerning the consequences of a delivery of off-spec fuel oil in the context of complex blending operations. Outstanding junior Thomas Crangle acted in a TCC dispute between Seflam and Nigerstar relating to the upgrade of a major oil pipeline on the Nigerian coast.

London Bar > International arbitration: counsel

(Leading Silks)Ranked: Tier 1

Sean Brannigan KC4 Pump CourtSean is absolutely outstanding – the leading construction silk. He is fantastic to work with and a real client favourite. He is excellent on strategy and his advocacy is a joy to behold.’

4 Pump Court is a ‘very strong set of barristers for complex document heavy arbitrations‘  and is commended for its ‘good strength in depth, in both the Silk and junior stables’. The set stands out for its versatility, with members offering excellent expertise in a range of key industries, including construction and engineering, IT, shipping and insurance. Members regularly work in teams or appear on opposite sides. Recently Sean Brannigan KC has faced off against Rachel Ansell KC in a major multibillion-dollar infrastructure dispute in the Middle East. Sean O’Sullivan KC is also leading Andrew Stevens in a significant cross-border shipping claim involving Chinese and Indian parties.

London Bar > Professional negligence

(Leading Silks)Ranked: Tier 2

Sean Brannigan KC4 Pump CourtSean combines a sharp intellect with practical insight.  His willingness to form part of the solicitor client team means total integration into the case and in turn confidence from the client.  His advocacy is incisive and penetrating without ever being disrespectful.’

Asia Pacific - The English Bar > Construction, energy and infrastructure

(Leading Silks)Ranked: Tier 1

Sean Brannigan KC – 4 Pump Court

4 Pump Court is a leading construction, energy and engineering set within the Asia Pacific region, with members having experience in all forms of energy and can deal with construction issues resulting from projects such as mining, drilling and exploration. Member of chambers can handle international disputes from all major arbitral centres and against bodies such as the ICC and LCIA. Sean Brannigan KC continues to be a first choice of counsel for many complex and high quantum construction cases. Alexander Wright KC was made silk in March 2022.

Middle East: The English Bar > Construction

(Leading silks)Ranked: Tier 1

Sean Brannigan KC – 4 Pump Court ‘Sean is a leader in his field. His legal and advocacy skills are second-to-none, but his real strength lies in his ability to communicate effectively with clients and solicitors alike.’

4 Pump Court has a strong reputation in construction and engineering disputes across the Middle East, and is noted for its involvement in significant infrastructure disputes, including rail, aviation and wider transport projects. Rachel Ansell KC is well-regarded for her international arbitration practice, particularly in relation to UAE matters. Sean Brannigan KC continues to act on large-scale, high-value infrastructure and engineering disputes and international arbitrations. Alexander Hickey KC is instructed on a range of disputes, including those involving airports and power and water projects. Claire Packman KC is another key name to note, and has been involved in a number of ICC arbitrations. Turning to the set’s juniors, Thomas Crangle specialises in major transport infrastructure-related disputes, whilst Luke Wygas has been involved in disputes involving airports and hotels.