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Mark Chennells

Call 2002

"Incredibly bright and fiercely hard-working, with an excellent style on his feet. He's one of the best."

Chambers and Partners

Mark has broad experience of acting both as sole counsel retained in proceedings and as junior counsel in very large commercially, legally and technically complex disputes with expertise in domestic and international arbitration, TCC and Commercial Court litigation, adjudication and mediation.

He specialises mainly in construction and engineering, professional negligence, IT and telecommunications, and energy disputes representing governments, a wide range of contractors, private employers and their professional advisors all over the world. He also has experience of issues of private international law, including the jurisdiction of the English and foreign courts and the determination of applicable law.

Mark is recommended by Chambers and Partners UK as a leading junior in the construction, energy and international arbitration fields. He is also recommended for construction in Chambers Global, by The Legal 500 as a leading junior in the fields of construction, international arbitration, energy and information technology, and by The Legal 500 Asia-Pacific for construction. Mark was awarded Construction Junior of the Year at the Chambers UK Bar Awards 2015.


Mark is familiar with the standard forms of contract in use in the industry and has experience of issues including delay and disruption to projects, variations and defects in design and construction as well as related commercial issues including issues relating to guarantees and performance bonds. He has been involved in disputes of widely varying size, value and scope, and has appeared before a variety of tribunals including in the Technology and Construction Court. His experience of construction and engineering disputes encompasses a wide range of industry sectors. He has extensive international experience as well as in domestic cases. Examples of his cases include:

  • Acting for US / Turkish joint venture in SIAC arbitration relating to termination of a contract for the design and construction of a road in challenging circumstances in the Middle East.
  • Acting for employer in a claim against developer concerning settlement of external hardstandings at new regional distribution centre: Travis Perkins v Roxhill
  • Acting for design and build contractor in respect of quay extension project and claim against engineering consultant retained to advise and produce designs, concerning subsea ground conditions: Kier v Hyder Consulting
  • Acting for dredging company in IAC arbitration respect of claims relating to Tawainese port project
  • Acting in an HKIAC arbitration relating to a dispute under a joint venture agreement. The project with which the joint venture was concerned was a HK$10b casino, hotel and retail development in Macau.
  • Acting for fit-out contractor in DIAC arbitrations on final accounts for work to new hotel
  • Acting in an ICC arbitration for a Norwegian company against its Tanzanian contractor in respect of a dispute relating to the design and construction of a fertilizer terminal in Dar es Salaam.
  • Acting for provider in a dispute under a PFI contract for the provision of management and other services relating to the M25 motorway: Connect Plus (M25) Ltd v Highways England Co Ltd [2017] BLR 33.
  • Acting for provider in a substantial dispute under a long-term highways maintenance agreement.
  • Acting for claimant services company in respect of claim relating to corrosion to steel chilled water pipework; Linklaters Business Services v Sir Robert McAlpine Ltd & Ors [2010] EWHC 2931 (TCC); [2011] BLR 108.
  • Acting for Portuguese joint venture in ICC Arbitration in Poland (hearings in Warsaw) relating to major infrastructure project procured under FIDIC contract.
  • Acting for well-known developer in six-week arbitration in Hong Kong relating to the contractor’s final account. Issues concerned, amongst other things, defects, delay, loss and expense and variations.
  • Acting for the employer in substantial arbitration in Dublin concerning claims arising out of a FIDIC-based design and build contract for a road.
  • Acting for a Spanish infrastructure company in respect of a HK$1bn arbitration relating to a major viaduct project in Hong Kong under HKIAC rules.
  • Acting in TCC proceedings for foreign government in dispute with Spanish contractor relating to termination of high profile infrastructure project under FIDIC form; Obrascon Huarte Lain SA v Her Majesty’s Attorney General for Gibraltar.
  • Acting for Multiplex Constructions (UK) Ltd in its disputes with P C Harrington Contractors Ltd, the main concrete sub-contractor in respect of the New Wembley National Stadium. Involved in significant adjudications, TCC litigation and related Part 8 High Court proceedings. See P C Harrington Contractors Ltd v Multiplex Constructions (UK) Ltd [2008] BLR 16.
  • Acting for a dredging and construction Sino-Dutch joint venture in arbitrations in Hong Kong (HKIAC Rules) concerning misrepresentations in tender documentation and disputed claims as to variations.
  • Acting for a main contractor in a substantial adjudication in respect of piling works at a prominent site, involving complex technical and geotechnical engineering issues.
  • Acting for contractor against utilities company in Part 8 proceedings relating to adjudications arising out of pipeline installation project; Wales and West Utilities Ltd v PPS Pipeline Systems GmbH [2014] BLR 163.
  • Acting for specialist M&E contractor in respect of defects in air conditioning system and corrosion of steel pipework; Verizon v NG Bailey & Ors.
  • Acting for contractor in claim against supplier of proprietary cladding system applied to tower blocks in Glasgow; Insulclad v Dryvit.
  • Acting for joint venture in respect of claims arising out of airport project procured on NEC3 contract.
  • Acting for the British government in a 12 week final account arbitration relating to a large scale road-building project. Issues included delay and disruption and variation claims.
  • Acting for the claimant utilities contractor in action concerning the assignment of proceeds of account under Rule 4.90 of the Insolvency Rules 1986 and the ability to adjudicate; Enterprise Managed Services Ltd v Tony McFadden Utilities Ltd [2010] BLR 89.
  • Acting for the contractor in a multi-party M&E dispute relating to PFI hospital contract; HpC Kings College Hospital v Costain & Ors.
  • Acting for a well-known Property Developer in a TCC action concerning a claim under an agreement relating to infrastructure made pursuant to the s.278 of the Highways Act 1980; Dorset County Council v Countryside Properties (Commercial) PLC.
  • Acting for a regional development agency in a direct claim against a sub-contractor arising out of the removal of goods from a project site. Issues included the operation of retention of title provisions in the JCT standard form of contract and claims under the Torts (Interference with Goods) Act 1977; South East England Development Agency & Ors v Pro-Fix Services Ltd.


He has wide experience acting for contractors on domestic and international disputes arising out of the design and construction of, among other things, power stations, offshore wind farms and waste water treatment plants as well as oil and gas disputes (infrastructure and otherwise). Examples of his work include:

  • Acting for offshore drilling companies in LMAA arbitrations arising out of construction and sale of semi-submersible drilling rigs from Korean yard, for deployment in North Sea.
  • Acting for consortium of oil majors in UNCITRAL arbitration arising of project for the design and construction of LNG facility in Africa.
  • Acting for Japanese company in arbitrations concerning claims arising out of failure of condenser unit at Russian refinery.
  • Acting for Danish contractor in two pieces of litigation arising out of contract for the design and construction of an offshore wind farm.
    • The first concerned the valuation of variation orders relating to the replacement of the installation vessel deployed on the project; MT Højgaard A/S v EON [2013] EWHC 967 (TCC); [2014] EWCA Civ 710; [2015] BLR 55.
    • The second concerned responsibility for the failure of the grouted connections in the foundations, and is the first piece of English litigation arising out of the industry wide design code failure that emerged in 2009. The case was heard by the Supreme Court in 2017; MT Højgaard A/S v EON [2014] BLR 450; [2015] BLR 431; [2017] BLR 477
  • Acting for Chinese steel fabricator in US$400m TCC action concerning manufacture and supply of steel structures for the Greater Gabbard offshore wind farm project: Fluor v ZPMC [2016] EWHC 2062 (TCC).
  • Acting for Dutch joint venture partners in an NAI arbitration concerning the design and construction of a test rig for the topside lifting systems of a new decommissioning vessel. Case fought to a conclusion in Rotterdam.
  • Acting for a drilling contractor in litigation arising out of the drilling of a well offshore Guinea. Issues relating to the LOGIC standard form and amendments to it, and allegations of delay and additional cost in the drilling of the well. Claims between concessionaire (a subsidiary of Hyperdynamics corp), the well project manager and the drilling contractor; Jasper v AGR; SCS v AGR.
  • Acting for drilling company in litigation arising out of the drilling of a well offshore Tunisia. Issues involving delay and cost associated with drilling of the well; Grup Servicii Petroliere SA v CE Tunisia Bargou & Ors.
  • Acting for supplier of condenser to operator of LPG terminal in claim relating to failure of system though corrosion of cupro-nickel tubing and related proceedings; Zueitina Oil Co v Hunt Thermal Technologies.
  • Acting for a global provider of technology-based “design and build” process facilities solutions to the upstream oil & gas industry in its Commercial Court claim relating to the supply of topside process modules for an FPSO to operate offshore New Zealand; Global Process Systems Inc v Tablelands Development Limited.
  • Acting for international energy company in respect of dispute arising out of hydro-power project.
  • Acting for owner in dispute over refurbishment and upgrade of semi-submersible drilling rig.
  • Acting for Japanese contractor in two ICC Arbitrations against European and Middle Eastern counterparties in respect of waste water treatment plant in the Middle East. Both arbitrations were fought to a final hearing in London.
  • Advising substantial shipbuilding company on claims with specialist international engineering company.
  • Advising an international energy company extensively in respect of its rights and liabilities, including in respect of claims intimated, under EPC contracts for the provision of new combined cycle gas turbine power stations. Issues considered include the scope of force majeure provisions, the operation of extension of time provisions and obligations in respect of the provision of spare parts.
  • Advising civil works contractor in respect of claims arising out of multi-fuels power project.
  • Acting for two Degremont companies, the subsidiaries of a French Utilities group, in a major TCC action concerning the design and construction of a secondary treatment plant at a waste water facility. In addition to dealing with issues concerning the performance of the plant in terms of output so as to enable compliance with an EC Directive (giving rise to issues as to the design, construction and operation of the plant), Mark was heavily involved in the stay of proceedings on an alleged parent company guarantee in favour of the exclusive jurisdiction of the French Courts and the claim arising out of the Group Action brought by local residents relating to alleged odour nuisance; United Utilities v Degremont & Ors.
  • Advising a well-known Far Eastern conglomerate on rights and liabilities under EPC Contract.
  • Advising a contractor on rights and liabilities under contract for provision of overseas waste water treatment plant.


Mark has significant experience of IT project disputes and has acted variously for client, supplier and consultants. Issues of which Mark has direct experience include (but are not limited to) payment and termination provisions in IT contracts, software design and defects, and delay in the provision of software. Recent matters include:

  • Acting for banking group in respect of its claim arising out of a major incident affecting the operation of its batch processing systems.
  • Acting for public body in expedited Commercial Court proceedings relating to termination of outsourcing contract: BT v Cornwall Council, Cornwall Partnership NHS Foundation Trust, Peninsula Community Health [2015] EWHC 3755 (Comm).
  • Advising data processing company in respect of contract with data storage provider.
  • Acting for defence company in respect of disputes relating to communications systems.
  • Acting for purchaser of software to facilitate multilateral settlement of payment obligations of member international banks.
  • Acting for a major mobile telecommunications provider in multi-party action in the TCC concerning a project for the provision of a new content and portal service delivery platform; T-Mobile International UK Ltd v LogicaCMG UK Ltd.
  • Acting for supplier of electronic ticketing machines in dispute with bus operator; Nottingham City Transport v Hoeft & Wessel.
  • Acting for a firm of management consultants in two multi million pound actions in the Commercial Court in relation to the ‘benchmarking’ of a global IT outsourcing deal in the telecoms sector. Issues included proper operation of service supply and payment provisions under outsourcing contract, benchmarking provisions and industry practice; IBM United Kingdom Ltd v Compass Management Consulting.
  • Acting for building society in dispute relating to complaints management software; Charter UK Ltd v Nationwide Building Society.
  • Acting for the Claimant in a multi-million pound TCC action concerning the provision of safety critical embedded software to a company engaged in the provision of mass transit rail systems. Issues included the operation of termination provisions under the contract, repudiation, defects and delay in the provision of the software. Westinghouse Rail Systems Ltd v Data Systems & Solutions Ltd.


Mark has acted as sole counsel and as junior counsel variously for and against engineers, architects, project managers and other consultants in the IT, construction and engineering sectors. Recent instructions include:

  • Acting for defendant engineering company in proceedings arising out of traffic modelling exercise and related advice; Secretary of State for Transport v Atkins.
  • Acting for third party architects in multi-party TCC litigation concerning delay and defective works; EEF Ltd v Sol Construction Ltd v Hodder Associates.
  • Acting for defendant architects in the TCC and in the Court of Appeal in relation to a claim by the occupier of a distribution warehouse arising out of a flood. Issues included the scope of an architect’s duty of care to ‘subsequent’ occupiers and the relevance of the opportunity for intermediate examination and discovery of design defects; Pearson Education Ltd v The Charter Partnership Ltd [2006] PNLR 14 (TCC), [2007] EWCA Civ 130 (CA).
  • Acting in a TCC claim for specialist designers of spa facilities for fees and allegations of professional negligence in relation to services provided; Corporate Edge Group Ltd v Champneys Tring Ltd;
  • Acting for management consultants in an action brought by an IT services supplier alleging negligence in the benchmarking of an outsourcing agreement; IBM United Kingdom Ltd v Compass Management Consulting.
  • Acting in arbitrations for a well-known engineering company relating to claims of professional negligence in the supply of multi-disciplinary consultancy services. The claims were arising out of a project in the education sector alleged to be over-time and over-budget.
  • Arbitrations against consultants involved in overseas airport terminal project.
  • Dispute under Partnering Agreement relating to structural engineering issues.


In addition to the specialist areas above, Mark is also instructed on general commercial disputes arising (such as sale of goods and bonds and guarantees), to include:

  • Acting in an arbitration relating to a contract for the provision of water extraction rights.
  • Advising in respect of security documentation concerning importation / exportation of vessel for offshore subsea surveying exercise.
  • Acting and advising extensively in a major dispute concerning the provision of a parent company guarantee in a major utilities project. Conflicts of laws issues included jurisdiction under the Judgments Regulation and the proper choice of law (including in respect of issues of authority); United Utilities v Degremont & Ors.
  • Advising in relation to calls on performance bonds and drafting of call documentation.
  • Acting for a well-known multi-national company in relation to the supply of specialist surveying equipment. The claims, which were successfully settled at mediation, were brought under the Sale of Goods Act 1979 in relation to amongst other things fitness for purpose and adequacy of firmware.
  • Acting for claimant power company in respect of claims under contract for installation of CHP units and energy supply; Combined Power (South) Limited v European Development Company.
  • Acting for a property development company in disputes concerning financing agreements for property development; 4Site Services Ltd v Calverley Properties (Kingswood Birches) Ltd.
  • Acting for an Australian manufacturer of specialist equipment in claims for breach of exclusive supply agreements with British companies; Bell Scaffolding (Aust) Pty Ltd v Rekon Ltd & Anor.


MTH Højgaard A/S v EON Climate & Renewables [2014] BLR 450; [2015] BLR 431; [2017] UKSC 59; [2017] BLR 477

Wales and West Utilities Ltd v PPS Pipeline Systems GmbH [2014] BLR 163

MTH Højgaard A/S v EON Climate & Renewables [2013] EWHC 697 (TCC); [2014] EWCA Civ [710]; [2015] BLR 55;

Fluor v Shanghai Zhenhua Heavy Industry Co, Ltd [2016] EWHC 2062 (TCC)

Fluor v Shanghai Zhenhua Heavy Industry Co, Ltd [2018] EWHC 1 (TCC)

Axis v Multiplex Europe [2019] EWHC 169 (TCC)

Connect Plus (M25) Ltd v Highways England Co Ltd [2017] BLR 33

BT Cornwall Ltd v Cornwall Council, Cornwall Partnership NHS Foundation Trust, Peninsula Community Health CIC [2015] EWHC 3755 (Comm)

Countryside Properties v MDS Civil [2009] EWHC 3418 (TCC);

Charter UK Ltd v Nationwide Building Society [2009] EWHC 1002 (TCC)

Linklaters Business Services v Sir Robert McAlpine & Ors [2011] BLR 108

Enterprise Managed Services Ltd v Tony McFadden Utilities Ltd [2010] BLR 89

P C Harrington Contractors Limited v Multiplex Constructions (UK) Limited [2008] BLR 16

Pearson Education Ltd v The Charter Partnership Ltd [2006] PNLR 14 (TCC), [2007] EWCA, Civ 130 (CA), [2007] BLR 324


2001-2002 – BVC, Inns of Court School of Law, London

2001 – Senior Mooter, Gray’s Inn

Lord Justice Holker Award Holder, Gray’s Inn

1998-2001 – MA Law (Upper Second), Gonville and Caius College, Cambridge University


Mark is a member of COMBAR, TECBAR and the SCL.


“He has a skill set that instructing solicitors dream of and would be at the very top of the list of juniors I would be delighted to recommend – he is an intellectual heavyweight with a masterful presence and yet also very accessible and client-friendly.” “A very astute, thorough, incisive and experienced junior.”

Construction, Chambers & Partners UK Bar 2020


“He is tough, clever and very personable.” “He is commercial and has a positive attitude.”

Energy, Chambers & Partners UK Bar 2020


“A great lawyer who is extremely modern in his approach.” “A really good cross-examiner.”

International Arbitration, Chambers & Partners UK Bar 2020


“Dedicated, with a great eye for detail.”

Construction, Energy & Infrastructure, The Legal 500 Asia-Pacific 2020



“He has a knack for suggesting different approaches which turn issues on their head and in your favour. “

Construction, The Legal 500 2020


“Clever with good instincts and very able to run whole sections of a big case on his own.”

Energy, The Legal 500 2020


“He offers considered analysis and instils confidence into his clients.”

IT and Telecoms, The Legal 500 2020


“Has a knack of popping up with slightly different answers and approaches which turn issues on their head and in your favour. “

International Arbitration, The Legal 500 2020


A very diligent and very bright junior who is just very good at thinking around and finding angles in cases.” “He’s very good with junior lawyers and clients,” and “produces very effective cross-examination.”

Construction, Chambers & Partners UK Bar 2019


“His written submissions are brilliant; he really adds value with his ingenious arguments.” “He is a diligent and very bright junior who is very good at thinking around things.”

Energy, Chambers & Partners UK Bar 2019


“Thorough, good on detail and very client-focused.”

Energy, The Legal 500 2019


“He is extremely hardworking, very bright and excellent to work with.”

IT and Telecoms, The Legal 500 2019


“Thorough, good on detail, and very client focused.”

International Arbitration, The Legal 500 2019


“A senior junior who is always enthusiastic and offers high-class work.”

Construction, The Legal 500 Asia-Pacific 2019


“Extremely hard-working, a real team player and great to have in any dispute team.” “Incredibly bright and fiercely hard-working, with an excellent style on his feet. He’s one of the best.”

Construction, Chambers & Partners UK Bar and Global 2018


“Extremely good, pleasant and unassuming.” “He’s very bright and good at the kind of work you’d normally give to QCs.”

Energy, Chambers & Partners UK Bar and Global 2018


“A very competent and able barrister with wonderful client skills.”

Construction, The Legal 500 Asia-Pacific 2018


“A smooth operator, who knows how to tell a story to his client’s advantage.”

Construction, The Legal 500 2017


“A well-regarded and experienced advocate.”

Energy, The Legal 500 2017


“He is good at identifying the key points in a case and focusing on them.”

IT and Telecoms, The Legal 500 2017


“He provides good legal analysis, stamina in evidence review and detailed pleadings.”

International Arbitration, The Legal 500 2017


“The standard of his written submissions is extremely high. His language is always persuasive and his mastery of detail shines through.”

Construction, Chambers & Partners UK Bar 2017


“He got his mind around a really complicated issue and did a very good job with it.” “He is hard-working and tenacious, crafts very clever arguments and is very good in terms of availability.”

Energy, Chambers & Partners UK Bar 2017


“He has a first-class intellect and a charming approach.”

International Arbitration, Chambers & Partners UK Bar 2017


“He has a first-class intellect and a charming approach.”

Construction, Chambers Global 2017


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.