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Hendersons - Barristers' Chambers

Kathleen Donnelly KC

"Kathleen is absolutely stellar."

Chambers UK 2025


Call
2005
Silk
2023

Kathleen specialises in group actions, product liability, environment and employment litigation.

Kathleen has acted in some of the largest and most significant class actions in the English Courts.  She acted for 555 subpostmasters against the Post Office in civil litigation concerning the operation of the Horizon IT system, resulting in the unravelling of the largest miscarriage of justice in UK history, with 93 convictions of innocent people for theft, fraud and false accounting overturned as a result of the findings in the High Court that the IT system contained bugs and errors and was not robust.

Kathleen acted in the long running VW NOx emissions litigation and continues to act in this field.  She has experience of large scale environmental claims including the OCENSA pipeline litigation (concluding in a 5 month trial) as well as workplace respiratory claims and private nuisance claims.  She acted for a major industry party at the Potters Bar inquest.

Kathleen has broad commercial litigation experience, including in the high profile aviation dispute between Qatar Airways v Airbus, and in the Stirling Mortimer fraud and professional negligence litigation.

Kathleen is instructed for a major retailer in a high profile equal pay claim.  She has particular experience of employee competition cases, and appears for international civil servants against the African Development Bank.

Chambers and Partners 2023 describe Kathleen as “a phenomenal barrister; her ability to retain detail is truly impressive”, with “a stunning ability to understand complex issues”, “really bright, commercial, and great strategic acumen”. Legal 500 describes her as “tenacious and persuasive”, “excellent with clients”, having “excellent advocacy skills that result in clients winning their cases” and being “very bright, tenacious and good on her feet”.

Chambers and Partners 2024 describe Kathleen as ” a superb barrister with a combination of fierce intellect, dogged work ethic, incredible grasp of detail, a superb manner with clients and a great sense of humour”, “absolutely fabulous… extremely well prepared and combines diplomacy with a forcefulness in arguing our case”, and “an expert in environmental law and group litigation”, and that  “Kathleen works endlessly and is the engine room for the case.” Legal 500 say “Clients and solicitors love her”, “Excellent with clients under pressure”, and “Razor-sharp mind and exceptionally strong on managing multiple work streams.”

Kathleen studied law at Oriel College, Oxford and has a postgraduate law degree from Queens’ College, Cambridge.


For more information about the way barristers at Henderson Chambers work, including our terms of engagement, fee transparency statement and our complaints process, please click here.  Barristers are regulated by the Bar Standards Board.

Please click here for a copy of Kathleen Donnelly’s privacy policy.

 

Expertise


Group Actions

Kathleen has acted in some of the largest and most significant group actions in the English Courts, including the Post Office litigation, the VW NOx Emissions litigation and the OCENSA pipeline litigation.

She is adept at dealing with strategic issues across multiple work streams, and leading a large team, including where multiple technical experts are involved.

Representative cases

grid list
  • VW NOx Emissions group litigation

    Acted for VW in this long running litigation (2015-2021) and instructed in the second wave of NOx emissions cases, in which allegations are made against the entire diesel industry.

  • Equal Pay group litigation
    • Acting for a major retailer in a high profile equal pay case being pursued by more than 2,000 staff members.
  • Post Office group litigation

    Acting for 555 subpostmasters against the Post Office in civil litigation concerning the operation of the Horizon IT system, resulting in the unravelling of the largest miscarriage of justice in UK history, with 93 convictions of innocent people for theft, fraud and false accounting overturned as a result of the findings in the High Court that the IT system contained bugs and errors and was not robust.

  • OCENSA pipeline group litigation

    Major environmental damage action concerning alleged environmental damage in Colombia, which concluded in a 5 month trial.

  • Sports Direct bonus group litigation

    Acting for Sports Direct in this employment related group action brought by part time employees.

  • Arkwright In Vessel Composting Site group litigation

    Private nuisance claim concerning odour.

Product Liability

Kathleen has significant product liability experience in complex multi-party actions, including where product safety issues arise.  She has particular experience in manufacturing, transport and energy related claims and dealing with technical expert evidence.

Representative cases

grid list
  • Qatar v Airbus

    Acting for Qatar in this high profile commercial dispute concerning the surface degradation and grounding of A350 aircraft.

  • VW NOx Emissions litigation

    Acting for VW in this long running litigation (2015-2021) and is instructed in the second wave of NOx emissions cases, in which allegations are made against the entire diesel industry.

  • OCENSA pipeline litigation

    Large scale group litigation concerning the construction of a pipeline in Colombia, which concluded in a 5 month trial.

  • Proceedings concerning the emissions compliance of forklift trucks.

  • Inquest concerning the death of a patient during cranial surgery using a surgical navigation system.

  • A claim for defective playground equipment.

Environment

Kathleen has acted in a number of large scale environmental group actions, as well as other high profile civil and criminal environmental proceedings. She has particular experience in waste, transport, mining and railway related cases.

Representative cases

grid list
  • VW NOx Emissions group litigation

    Acted for VW in this long running litigation (2015-2021) and instructed in the second wave of NOx emissions cases, in which allegations are made against the entire diesel industry.

  • Arkwright In Vessel Composting Site group litigation

    Private nuisance claim concerning odour.

  • OCENSA pipeline group litigation

    Major environmental damage action concerning alleged environmental damage in Colombia, which concluded in a 5 month trial.

  • Powertrain group litigation

    Claim concerning alleged respiratory complaints arising from exposure to metal working fluid.

  • HSE v UK Coal, Alstead and Davison

    Prosecution arising from a fatal accident at Daw Mill Colliery.

Employment

Kathleen is an established employment practitioner and experienced in employment tribunal and high court work. Kathleen has particular experience of employee competition cases, discrimination and whistleblowing claims.  She is currently instructed for a major retailer in a high profile equal pay claim.  She appears for international civil servants against the African Development Bank.

Representative cases

grid list
  • Equal Pay group litigation

    Acting for a major retailer in a high profile equal pay case being pursued by more than 2,000 staff members.

  • Advising CEO of major UK fashion brand in a claim for whistleblowing and sex discrimination.

  • Jerroms v Tilson

    Employee competition and economic tort claim.

  • Advising CEO of major UK PR brand in claim for bonus and sex discrimination.

  • Aron v AFDB

    Claim for unlawful termination for abandonment of post.

  • Michelitsch v AFDB

    Acting for former Evaluator General against the AFDB.

 

What the directories say


"Kathleen's cross-examination is beyond exceptional."
Chambers UK 2025

"Kathleen is fantastic."
Chambers UK 2025

"I think she's great and hugely impressive."
Chambers UK 2025

"She is wonderfully articulate, clear, concise and commercial."
Chambers UK 2025

"I've found her to be user-friendly and a great team player."
Chambers UK 2025

Instructing Kathleen Donnelly KC

If you require help or advice please contact our clerking team

Call +44 (0)20 7583 9020
or email

Appointments
  • King’s Counsel (2023)
Memberships
  • Commercial Bar Association
  • Employment Lawyers Association
  • Personal Injuries Bar Association
Education
  • LLM Commercial and International Law (Cantab) (2003)
  • BA (Hons) Jurisprudence (Oxon) (2001)
  • Hardwicke Award, Lincolns Inn
  • Buchanan Scholar, Lincoln’s Inn
Regulatory Information

All members of Chambers are registered with the Bar Standards Board of England and Wales. For our standard contractual terms click here.

For more information about the way barristers at Henderson Chambers work, including our fee transparency statement and our complaints process, please click here.

Bar Council Number: 48049

VAT Registration Number: 877522195

Legal Status: King’s Counsel

Professional Insurance: All members of Chambers have professional liability insurance provided by the Bar Mutual Indemnity Fund Ltd. Territorial coverage is world-wide and subject to the term of the Bar Mutual. Click here for details.

Regulated by the Bar Standards Board.

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