Instruct Jonathan

To instruct Jonathan please contact our clerks on +44 (0)20 7842 5555 or email

Jonathan Marks QC has a wide ranging civil practice.

Jonathan has a wide ranging international civil practice. He has a reputation as a formidable and versatile advocate, particularly in cross-examination. He appears before a wide range of courts and tribunals and appears frequently in arbitrations in England and Wales and other jurisdictions, particularly in the Middle East. He is often instructed in cases involving highly technical material and regularly deals with sophisticated expert evidence.

Jonathan also has extensive experience of representing clients at mediations. He is a qualified arbitrator and mediator and is happy to accept appointments. He has wide experience of complex negotiations, often involving related disputes in different jurisdictions and areas of law.

He has particular expertise in:

  • Construction & Engineering
  • Commercial Dispute Resolution
  • Professional Negligence

Jonathan is highly regarded in this field and has developed an extensive construction and engineering practice in England and Wales and overseas, particularly in the Middle East. He regularly appears before arbitrators and judges in the Technology and Construction Court and has considerable experience of conducting arbitrations in the Middle East, remotely as well as in person.  He is frequently instructed in cases involving highly technical material.

Jonathan’s clients include major corporations, government departments and agencies, national and international companies, contractors and developers.

Featured Construction & Engineering cases

Conducting a substantial arbitration in the UAE under ICC rules, representing an employer in a dispute arising out of the construction of a large mixed use (residential, office, retail and medical) development in the UAE under a FIDIC contract. Serious technical issues concerned the construction of the basement and the ability of the floor slabs to withstand hydrostatic pressure  and contractual issues included rights to terminate under the FIDIC contract and their interplay with UAE Law.

Representing a German client in a long international arbitration under ICC rules concerning the supply and installation of all the plant and processing equipment in a substantial new factory in the UK. Case involved detailed engineering and process evidence, as well as lengthy and complex factual evidence and consideration of the concept of “willful default”.

Representing the main Contractor in a major dispute with an employer arbitrated under DIAC rules arising out of a FIDIC contract for the construction of four blocks of flats. The arbitration, in the UAE, involved two evidentiary hearings and detailed consideration of construction delays and their causes and allegations of defective construction. There were substantial technical issues and the Tribunal appointed an independent engineering expert of their own, in addition to the parties’ own experts.

Appearing for the Respondent M and E contractors in successfully resisting an appeal to the TCC by the main contractor against an award by an arbitrator on points of law, involving legal arguments about the burden of proof, a “global costs” claim.

Representing a major construction company in a substantial Defective Premises Act action in the TCC, brought by multiple claimants, arising out of the construction of two blocks of flats in Leeds and a further action; the claims involved novel points of law on class actions and the measure of damages in Defective Premises Act cases.

Representing contractors in the Court of Appeal in a construction case involving points of law on appeal on the status of an adjudication award and the effect of Calderbank letters on costs; brought in to conduct appeal after adverse decisions below.

Acting for structural engineers in successfully resisting a claim arising out of the design and installation of the concrete floor for a major warehousing operation.

Acting for a multinational train contractor in a dispute with an international electronics company; the client claimed damages for the supply of defective electronics systems; the case involved a series of arbitrations and many technical issues.

Instructed by a government agency in an arbitration concerning the contract administration of a major flood relief tunneling project, involving an investigation of the performance of sophisticated tunneling machinery.

Acting for the contractor in a dispute involving the delays to a substantial railway bridge building project.

Instructed by the owner in a contractual dispute relating to a shipbuilding contract in the Far East.

Acting for the main contractor in a long-running dispute concerning construction works involved in the implementation of a city centre pedestrianisation project.

Acting for the claimant in a claim by purchasers of a production line and ovens for food production.

Acting for major national cleaning contractors in a case involving a fire at Waterloo Station, London; the case raised technical questions concerning the causes of the start and spread of the fire; the case settled after mediation.

Acting for a major train contractor on an underground network in an adjudication fought under the terms of a PFI contract; the case involved difficult contractual issues as to entitlement to extra monies under the terms of contract for removing asbestos from equipment on tube line.

Regularly engaged by major roofing contractors in disputes with subcontractors and employers; cases have involved shopping centres, office developments and town centre developments, and include adjudications and enforcement of adjudications.

Acting for the manufacturers of glazing and window systems in resisting claims from purchasers blaming window failures on manufacturing defects rather than installation failures.

Acting for the installers of cavity insulation material in claims against the manufacturers arising out of the product’s vulnerability to water ingress.

Jonathan’s work in this area involves a wide variety of contractual and other commercial disputes, many with an international dimension, litigated or arbitrated in England and Wales or in other jurisdictions. He is particularly experienced at undertaking cases with sharp disputes of fact requiring rigorous cross-examination.

Featured Commercial Disputes cases

Represented an overseas insurer in an action brought by solicitors challenging the right of insurers to settle road traffic claims directly with road traffic claimants without incurring a liability to meet the solicitors costs. Appeared at first instance in the Mercantile Court in Wales, then in the Court of Appeal and finially in the Supreme Court.

Represented a UAE joint stock public company and its major shareholder in a dispute with a minority shareholder in an arbitration in the UAE under DIAC rules. Contracts subject to UAE law. Wide ranging factual disputes and expert evidence on UAE law and company valuation.

Advising the guarantors of Chinese charterers in respect of an appeal to the Court of Appeal against a Commercial Court judgment to the effect that a charterparty was enforceable notwithstanding the conviction of the General Manager of thee shipowner for bribery in procuring the charterparty, which would have rendered the charterparty unenforceable. The casse involved complex issues of criminal law and the law of evidence and of recognition of the decisions of foreign courts.

Advising substantial UK developers on contractual issues arising out of a competitive land acquisition dispute.

Representing a UK investor in injunction proceedings against a Far Eastern investment banking and stockholding company concerning the misuse of shares pledged as security and the proceeds of sale thereof.

Representing the owner and operator of commercial helicopters in an international dispute about the acquisition of a helicopter and the misuse of funds placed in escrow for the purpose of the purchase.

Won a significant appeal against HMRC on liability for VAT of parking control contractors; brought in on the appeal to the Court of Appeal to replace specialist tax counsel to argue points of law on contract and trespass. Later contested a decision by HMRC in the First-Tier Tribunaal and then the Upper Tribunal to disallow a high proportion of the input tax reclaimed by the contractors.

Acting for a property investment group in an action for fraudulent misrepresentation and breach of warranty arising out of a corporate acquisition where the target company was the owner of a mixed retail/office development where the status of a number of commercial tenancies was misrepresented to the client buyers.

Representing a well-known public figure in an action in the Chancery Division concerning a dispute with an investment adviser and manager relating to the acquisition, ownership, management and disposal of a number of commercial investment properties.

Acting for a property developer in a misrepresentation claim against his co-joint venturer in respect of a substantial commercial site in London.

Representing a substantial overseas insurer at first instance and in the Court of Appeal in a dispute concerning direct settlement of motor claims between insurers and claimants.

Representing a county council in resisting multiple substantial negligence claims arising out of a major warehouse fire in the North of England.

Advising a financial services executive in a long running dispute with his former partners, resulting in a successful outcome for the client’s business.

Representing a stud owner in a High Court action in Leeds concerning ownership of a bloodstock business and a valuable stallion.

Representing a bloodstock agent in substantial litigation in the Chancery Division against his racehorse owner and show jumping client concerning alleged breach of fiduciary duty, misrepresentation and contractual disputes and tax issues.

Representing a property developer in a restitution claim against a local authority involving an abortive proposal to develop a cattle market.

Representing the controlling shareholder of a removals company in successfully resisting a contractual and equitable claim in the Chancery Division to be entitled to a shareholding in the company brought by a former executive.

Acting for a substantial and prominent property developer in various property disputes including a reported case involving a successful claim for possession of development land in the Midlands.

Representing the insurers of multiple Claimants in the TCC in respect of a fire claim arising out of the destruction of a substantial warehouse and all its contents; the case involved factual disputes plus technical fire questions and difficult points on vicarious liability.

Represented a major waste contractor, SITA, in the QB and the Court of Appeal (though the other side abandoned its appeal), in successfully resisting a commercial claim arising out of the cancellation by a local authority of a long running refuse contract to provide waste services.

Jonathan represents both claimants and defendants in a wide range of professional negligence actions involving lawyers, accountants, pension brokers, architects, surveyors, valuers, engineers, and members of the medical profession.

Featured Professional Negligence cases

Representing a major clearing bank in an action in the TCC and then in the Court of Appeal against a firm of projects monitor arising out of a substantial redevelopment of North London.

Acting for estate agents in major professional negligence and breach of fiduciary duty litigation arising out of an office, retail and residential development in the Midlands; successfully resisted an extension of time for service of Particulars of Claim in the TCC, resulting in the clients escaping liability.

Acting for one of a number of joint venturers in a claim against solicitors arising out of an inadequately documented transaction.

Acting for the sellers of a business in a claim against accountants for negligence involving failure to investigate the buyers’ ability to meet their liability to pay instalments after purchase.

Acting for the largest car wash company in Europe in a solicitors’ negligence action arising out of the acquisition of a German subsidiary; complex acquisition and mergers procedures and questions concerning allocation of contractual responsibility.

Acting for claimants and defendant solicitors in cases involving the financing, acquisition, development and refurbishment of property.

Instructed by claimants and defendant solicitors in cases involving allegedly mishandled property transactions and the conduct of litigation.

Acting for claimants and defendant solicitors in cases involving allegedly mishandled ancillary relief proceedings on divorce; Jonathan also has considerable experience of handling “big money” family law cases.

Acting in accountants’ negligence cases involving advice on complicated tax provisions such as relief on loans to closed companies, building society taxation, partnership taxation, as well as advice on corporate acquisitions and company accounts.

Acting for both claimants and defendants in numerous major clinical negligence cases including a dental operation severing a nerve; osteotomy in the foot causing disability; loss of babies at term because of errors in obstetric care; a patient awake during a Caesarian because of badly administered anaesthetic; Cauda equina lesion of the back caused by failure of diagnosis and failure to operate; defending an osteopath alleged to have damaged back during manipulation.

Jonathan has experience of professional regulatory tribunals and the Adjudication Panel for England. He has chaired a number of disciplinary hearings for the General Council of the Bar.

Featured Regulatory cases

Representing a surveyor before an RICS Disciplinary Panel in proceedings arising out of the insolvency of his partnership attributable to the defaults of his partner.

Representing a solicitor before the Solicitors Disciplinary Tribunal in proceedings arising out of a client’s improper property transactions.

Representing a councillor before the Adjudication Panel for England arising out of complaints about her conduct of council business.

Representing the Inns of Court in an appeal to the Visitors against a Barristers Disciplinary Tribunal.

Chairing Summary Procedure Panels and appeals from Adjudication Panels, as well as sitting on adjudication panels, for the Bar Standards Board and the Council of the Inns of Court.

As counsel, Jonathan has extensive experience in arbitration, adjudication and mediation. He is a fellow of the Chartered Institute of Arbitrators and accepts appointments as arbitrator, adjudicator and mediator.

Rankings in The Legal 500 EMEA Guide 2020

4 Pump Court are delighted that Members of Chambers have been recognised for their construction work in the Middle East...

Rankings in Legal 500 EMEA Guide 2019

4 Pump Court are delighted that Members of Chambers have been recognised for their construction work in the Middle East...

Instruct Jonathan

To instruct Jonathan please contact our clerks on +44 (0)20 7842 5521 or email

  • TECBAR approved adjudicator
  • Trained mediator
  • FCIArb
  • BA (Oxon) Jurisprudence
  • French (working knowledge)
  • Greek (working knowledge)

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