Debbie Grennan

Year of call: 1997

"She's tremendous: she's very strong, very diligent and very sensible."
Chambers UK 2019

Debbie Debbie

Debbie is a highly sought-after and experienced employment & discrimination barrister.

Employment & Discrimination

Debbie has a balance of claimant and respondent work which covers all aspects of employment and discrimination issues, as well as trade union law. She appears in the Court of Appeal and the Employment Appeal tribunal, as well as in the High and County Courts and employment tribunals.

Debbie represents parties from the public and private sectors. Her work regularly involves complex cases of whistle-blowing, discrimination, TUPE and related matters as well as claims in respect of restrictive covenants and injunctive relief. She is experienced in dealing with equal pay litigation and is currently instructed in two separate sets of multi-party public sector claims on behalf of local authorities and further equal pay litigation brought by a very senior employee against one of the UK's leading banks. She also advises and appears in respect of trade union matters, including issues relating to recognition, collective agreements and industrial action.

Debbie's employer clients include:

  • Local authorities
  • NHS Trusts & Health Boards
  • The Met Office
  • Schools
  • Clearing banks

Debbie's employee clients include senior employees from various professions including celebrity chefs and football club directors to medical professionals and senior oil industry and public sector workers.

Debbie is on the EHRC panel of approved barristers.

Significant Cases

  • Gallop v Newport City Council [2013] A2/2012/2073 (CA) and UKEAT/0586/10 (EAT) - Dealing with the requirement of knowledge of disability and (in the EAT only) the admissibility of without prejudice communications when assessing compensation for unfair dismissal.
  • Plymouth City Council v White UKEAT/0333/13 - Relating to the correct test for specific disclosure of documents.
  • Obokoh v Hywel DDA Health Board UKEAT/0407/12 - Dealing with the correct approach to wasted cost orders against a party's representative.
  • Obokoh v Hywel DDA Health Board UKEAT/0089/12 - Relating to SOSR dismissals and immigration status.
  • Somerset County Council v Chaloner UKEAT/0600/12 - Dealing with the correct approach to redundancy dismissals in the context of a business reorganization.
  • Singh v Bristol Sikh Temple UKEAT/0429/11 - Relating to the employment status of a Sikh priest.
  • Wheelers (Westbury) v Smallwood UKEAT/0455/10 - Regarding Service Provision Changes under TUPE.
  • Hooley v Truro School UKEAT/0234/10 - Dealing with causation of loss and assessment of damages in unfair dismissal claims.
  • Cherrington v Plymouth City Council UKEAT/0449/09 - Relating to the definition of a protected disclosure in the context of whistle-blowing.
  • Wright v Weed Control Ltd UKEAT/0492/07 - Dealing with the jurisdiction of employment tribunals to hear cases for breach of confidence.
  • Ranger v BIT Systems UKEAT/0049/07 - Relating to unfair dismissal and the failure of the ET to have regard to all material facts.
  • Walker v Hiberna FM Ltd UKEAT/0242/06 - Dealing with territorial jurisdiction in respect of a civilian working in Kosovo.
  • Mark Insulations v Bunker UKEAT/0331/05 - Concerning continuity of service under the ERA.
  • Scorah v Thomas UKEAT/0577/05 - Relating to Polkey deductions.

Professional Discipline

Disciplinaries & Appeals

Debbie deals with all types of internal disciplinary and appeal processes. For employers, she has chaired internal hearings and on other occasions has provided specialist employment advice in respect of their processes and decisions. For employees, Debbie has particularly expertise in dealing with cases which have potentially career-ending consequences, most notably for senior medical staff and headteachers.

Healthcare Regulation

Debbie regularly undertakes work in respect of proceedings before professional regulators. Recent work includes advising and appearing in proceedings before the General Medical Council, the General Dental Council, the General Optical Council and the Nursing and Midwifery Council.

Debbie's work encompasses both interim and final hearings.




Leading Junior - Band 1

Highly regarded for her expertise in high-value and complex discrimination and whistle-blowing claims, as well as matters relating to equal pay and TUPE. She regularly receives instructions on behalf of respondent local authorities and the NHS. She appears before the Employment Appeal Tribunal (EAT) in addition to her civil court practice.

Strengths: “Calm, collected, meticulously prepared and very persuasive. Watching her unravel a case through cross-examination is better than going to the theatre.”

Recent work: Represented the claimant in an age discrimination case against BAE Systems. The case concerned a tapering provision in an enhanced redundancy scheme.

LEGAL 500 2017


Leading juniors

‘Experienced in equal pay litigation.’



Leading Junior - Band 1

Highly regarded for her expertise in high-value and complex discrimination and whistle-blowing claims, as well as matters relating to equal pay and TUPE. She regularly receives instructions on behalf of respondent local authorities and the NHS.

Strengths: "She has complete knowledge of her brief and is calmness personified."

Recent work: Represented the claimants in a high-profile whistle-blowing case brought by two senior employees against two NHS trusts. The claims were successful, leading to a number of resignations and significant settlements.

LEGAL 500 2016


Leading juniors

'An employment law specialist.'  



Leading Junior - Band 1

Well reputed for her handling of complex whistle-blowing and discrimination cases, along with TUPE and equal pay claims. She receives a large number or instructions from NHS and local authority respondents.

Strengths: "She's a very effective presenter, a feisty cross-examiner and a robust advocate." "Good with clients, sharp on her feet, and involved closely even before the hearings."

Recent work: Represented the claimants in Sardari & Gates v Torbay and Southern Devon Health & Care NHS Trust and South Devon Healthcare NHS Foundation Trust, a high-level whistle-blowing matter which ultimately led to internal investigations at the organisations concerned.

LEGAL 500 2015


Leading juniors

'Her advice is always focused, clear and pragmatic'.

Debbie Grennan recently represented two employees in a high-profile whistleblowing case against two NHS trusts.



Leading Juniors (Band 1)

One of the Western Circuit's leading employment barristers, with vast NHS and local authority-related experience. She is noted for the breadth of her practice, which covers discrimination, whistle-blowing, TUPE and equal pay-related claims.

Expertise: "She is incredibly intuitive in terms of knowing what you want to achieve and finding the quickest way to get you there. If you ask her to do something you know it will be done quickly, but you can also be safe in the knowledge that everything is going to be done properly." "She is an excellent advocate, clear and concise in the advice which she provides."

Recent work: Represented Newport City Council as the respondent in a case at the Court of Appeal concerning a complex disability discrimination issue.

Who's Who Legal - UK Bar 2015

The "incredible" Debbie Grennan. She is a "calm authority" on matters involving equal pay, whistleblowing, driscrimination and TUPE.

LEGAL 500 2014


Leading juniors

'She has expertise in complex whistleblowing and discrimination cases, as well as TUPE and equal pay'.



Has considerable experience of employment law disputes. She handles a mix of claimant and respondent work related to all aspects of employment law, and also acts on trade union cases.

Expertise: "She is an excellent advocate, clear and concise in the advice she provides, and very approachable."

Recent work: He was instructed in a high profile EAT appeal concerning the issue of the employment status of a Sikh priest.

LEGAL 500 2013

Other recommended members of the 'very strong' group include Debbie Grennan.

LEGAL 500 2012

Debbie Grennan has particular expertise in discrimination and whistle-blowing claims.

LEGAL 500 2011

'Debbie Grennan's responses are prompt, apposite and down to earth; and her business acumen is faultless'.

LEGAL 500 2010

'Mixes a delightful and reassuring approach with clients with real grit and determination in the Employment Tribunal'.

LEGAL 500 2009

'Debbie Grennan has loads of ability and is user-friendly too'.

LEGAL 500 2008



For further information and enquiries please contact:

Employment & Discrimination: Kate Hather



  • Employment Lawyers Association
  • Employment Law Bar Association
  • Industrial Law Society
  • Western Circuit


  • LLB Hons
  • LLM, Medical Law & Ethics
  • Bar Vocational Course
  • Winner of the Lady Shaw prize as the highest placed female Grays Inn student