Manus McMullan KC

Silk 2010

"Incredibly hard-working and really bright."

Chambers and Partners

International Arbitration Silk of the Year 2018, Legal 500 UK Awards

International Arbitration Silk of the Year 2017, Chambers UK Bar Awards

Construction Silk of the Year 2016, Chambers UK Bar Awards

Energy and Construction Silk of the Year 2015, Legal 500 UK Awards


Manus specialises in commercial disputes with an emphasis on energy, natural resources and utilities, construction and engineering, professional indemnity and insurance matters both domestically and internationally. He is often the lead advocate on the largest and most high-profile disputes in these fields. He has represented a wide range of clients including multi-national corporations, government entities, professional advisers, contractors and individuals all over the world.

In the past three years, in cases where Manus has been acting for the Claimant or Plaintiff, his clients have been awarded, and have recovered, over US$ 1bn. In the same time frame, where he has been acting for Defendants or Respondents, he has successfully defended claims for in excess of US$ 5bn.

Manus is recommended by both The Legal 500 and Chambers and Partners in the fields of international arbitration, construction, energy and natural resources, and professional negligence.



Manus has experience of the whole range of disputes that arise in all varieties of construction and engineering projects including variations, defects, loss and expense, prolongation and acceleration. As well as dealing with such claims he has been instructed in cases involving fires, floods, structural collapse and subsidence.

In relation to engineering disputes his case load has covered the chemical, civil, electrical, electronic, geotechnical, industrial, manufacturing, marine, mechanical, piping, process, structural and tunneling disciplines. He has also been involved in technical engineering disputes concerning defective equipment, machinery and systems of all kinds.


Manus’ practice includes acting for parties concerning the development and exploitation of oil and gas fields all over the world, as well as the extraction and processing of other natural resources and minerals. Domestically, his work in utilities is more broadly-based. He has acted for and against utility providers (water, electricity and gas) in disputes with developers and also on projects such as power plants and sewage treatment works. In addition to cases concerning development, he has advised and fought cases upon the statutory framework in England and Wales and the rights and duties provided thereby. Matters include disputes over payment rates for renewable energy, royalties, and energy service agreements.


Manus has acted for and against many professionals, particularly in the construction and engineering fields. Cases have involved architects, engineers of many different disciplines, project managers and quantity surveyors as well as valuers, building surveyors and other designers.

He also acts in some cases of alleged professional negligence in other fields. On more than one occasion he has acted in cases concerning negligent legal drafting and advice, and against management consultants for failure to perform. As a result of his experience in information technology, he has acted for and against software designers.


In addition to the specialist areas referred to above, Manus is often instructed in disputes that concern other areas of commerce. He has experience of licence, distribution, royalty and franchise agreements. He was junior counsel in the House of Lords in a case concerning the effect of joint insurance.  He has fought a number of cases concerning bonds and guarantees. He has argued cases on jurisdiction and at times his cases concern insolvency.


2007: Called to the bar of Northern Ireland

2004: Ad hoc call to the bar of the Cayman Islands

1994: Called to the bar of England and Wales

1991: 1st Class Honours, Oxford University (Jurisprudence).


Manus is fluent in Spanish and has competent professional proficiency in French.

He is a member of the disciplinary board of the RIBA and a trustee of the Harold G Fox Scholarship.


“Manus is very experienced and knows the facts of a case inside out. He is super smart, quick thinking, with a great sense of humour and excellent communication skills vis-à-vis the client and the co-counsel, making everybody feel at ease. He engages with everybody and makes collaboration very pleasant.”
Construction, The Legal 500 2024

“Manus is a fierce cross-examiner and a highly articulate advocate who is very good at reading a tribunal and addressing its concerns.”
Energy, The Legal 500 2024

“No doubt Manus is top-notch and one of the very best in the field of oral advocacy and cross-examination, especially in complex high value disputes in the field of construction and engineering. His cross-examination is simply first-rate, excellent and truly outstanding – he has the special ability to explain complex technical aspects in a straightforward and understandable way.”
International Arbitration, The Legal 500 2024

“Manus has many strengths. He is a fierce cross-examiner and a highly articulate advocate. He excels at complex cross-examination of expert witnesses.”
Professional Negligence, The Legal 500 2024

“Manus McMullan is brilliant in all facets; his advocacy is inspiring and he is incredibly cool under the highest of pressures. Manus is also a pleasure to work with, day in, day out.”
“He is excellent in court.”
“His court craft is very good, and he knows a hell of a lot about construction and energy.”
Construction, Chambers UK Bar 2024

“He listens, distils, packages and presents fearlessly and sure-footedly.”
“One of the best barristers I have seen in action.”
“His cross-examination is simply first-rate, excellent and truly outstanding.”
International Arbitration: Construction/Engineering, Chambers UK Bar 2024

“Manus is an outstanding advocate with excellent analytical skills; his advice is always clear, to the point and convincing.”
“He has brilliant knowledge of the law, he’s tactically extremely astute, extremely experienced and he’s able to handle some of the biggest disputes in the world.”
Construction, Chambers UK Bar 2023

“He’s an absolutely excellent advocate.”
Energy & Natural Resources, Chambers UK Bar 2023

He’s just superb. I’ve been watching him cross-examine and he very much takes the lead strategically.”
“Clients love him; he’s outstanding.”
Professional Negligence: Technology & Construction: Chambers UK Bar 2023

“Manus is a superior advocate. He has excellent judgment and a first-rate legal mind, his cross-examinations are incisive and powerful, and his oral arguments are crisp, persuasive and go straight to the heart of the matter.”
Construction, The Legal 500 2023

“A superior advocate with excellent judgment and a first-rate legal mind, his cross-examinations are incisive and powerful.”
Energy, The Legal 500 2023

“A very authoritative advocate with an outstanding ability to master the most complex of cases. Manus has excellent analytical skills and gives clear and very pertinent advice based on a thorough review of the relevant material.”
International Arbitration: Counsel, The Legal 500 2023

“He’s very good on his feet, good with clients and good at looking at the big picture.”
“A complete superstar, who is calm and produces assured advocacy and drafting.” “He was brilliant at every instance: shrewd, credible, direct.”
Construction, Chambers UK Bar 2022

“He is a very talented individual and one who can handle every situation.”
“He is incredibly well respected and bright.”
Energy, Chambers UK Bar 2022

“A complete superstar who is calm and produces assured advocacy and drafting.”
“He was brilliant at every instance: shrewd, credible, direct. All in all, we were very happy to be working with him.”
Professional Negligence, Chambers UK Bar 2022

“He is an excellent barrister. He is very well respected among his peers and the legal community. He is a brilliant cross-examiner, and he has the ability to give an immediate and smart response to the unexpected.”
International Arbitration, Chambers UK Bar 2022

“Manus always has a problem solving attitude which is very helpful in an environment when different interests are at stake. He is a brilliant cross-examiner.”
Construction, The Legal 500 2022

“Extremely highly intellectual and substantial knowledge on relevant areas of law, and extensive experience with international arbitration which shines through in his work.”
International Arbitration, The Legal 500 2022

“He shows precision to detail and strategic planning and has an extremely high intellect and extensive experience in international arbitration.”
Energy, The Legal 500 2022

The above are a selection of recent client endorsements from the leading legal directories, both UK and internationally. For a complete list of endorsements, please contact the practice management team at Atkin Chambers.