Debbie Grennan

Call 1997

"Debbie is absolutely top notch and the full package: calm, collected, polished, well prepped and superbly knowledgeable, and her advocacy is a delight to watch."

For enquiries please contact

Caroline Evans
Senior Practice Manager - Civil
0117 930 9000
Click here to email

Rob McDonald
Practice Manager - Employment, Costs & Litigation Funding
0117 930 9000
Click here to email

Charlie Georgeson
Assistant Practice Manager - Personal Injury, Clinical Negligence, Employment & Discrimination, Court of Protection (Health & Welfare), Costs & Litigation Funding
0117 930 9000
Click here to email

"Debbie is absolutely top notch and the full package: calm, collected, polished, well prepped and superbly knowledgeable, and her advocacy is a delight to watch."


Chambers & Partners 2025

‘Debbie is simply superb – pragmatic, personable, knowledgeable, painstaking and to the point. She puts clients at ease and engenders complete confidence.’


Legal 500 UK 2023

"She is knowledgeable, pragmatic and clear-thinking, with superb advocacy skills."


Chambers & Partners UK 2023

"Debbie's courtroom skills are exceptional. She is crystal clear on paper and in person, and always puts the client at ease."


Legal 500 2021

"A fantastic advocate and very client-friendly. She engages with the client and is able to distil complex factual and legal issues in layman's terms. She is calm and collected and gets the best out of witnesses. You definitely want her acting for your side!"


Chambers UK 2021

"She's tremendous, she's very strong, very diligent and very sensible."


Chambers UK 2019

"She's a very effective presenter, a feisty cross-examiner and a robust advocate."


Chambers UK 2016

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


Who's Who - Legal Bar 2015

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

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

Debbie Grennan is a highly sought-after and experienced Employment & Discrimination barrister.

Debbie Grennan is highly regarded for her expertise in high-value and complex discrimination and whistleblowing claims, as well as matters relating to equal pay and TUPE.

She regularly receives instructions on behalf of respondent local authorities and the NHS. In addition to her civil court practice, she appears before the Employment Appeal Tribunal (EAT).

Expertise

Debbie has a balance of claimant and respondent work which covers all aspects of Employment & Discrimination law, as well as Business Protection & Trade Union law. She appears in the Court of Appeal, the Employment Appeal Tribunal, the High Court and County Courts, as well as the Employment Tribunal & Special Educational Needs (SEND) Tribunal.

Debbie represents parties from public and private sectors. Her work regularly involves complex cases of whistleblowing, Health & Safety, discrimination, Transfer of Undertakings Protection of Employment regulations (TUPE) and related matters, as well as claims in respect of restrictive covenants and directors/fiduciary duties.

She is experienced in dealing with equal pay litigation and has been involved in very large public sector equal pay claims on behalf of both local authority employers and groups of employees, as well as private sector claims relating to large clearing banks.

She advises in respect of Trade Union matters, including issues relating to recognition, collective agreements & industrial action.

Debbie has particular expertise in the area of overlap between Employment and Insolvency law. She also advises and appears in the SEND Tribunal and undertakes Civil Equality Act claims in respect of  matters such as the provision of services and education.

Debbie’s Employer Clients include Local Authorities, NHS Trusts, Schools, Clearing Banks, Large National & Multinational Businesses and a large number of Solicitors’ firms, who appreciate her commercial outlook, pragmatism and ability to quickly get to the heart of the problem finding solutions which work for their organisations.

Her employee clients include professionals from various sectors, from celebrity chefs and football club directors to medical professionals, senior public and private sector directors and employees as well as Legal & HR professionals.

She is regularly instructed to advise in relation to TUPE transfers, restructuring and redundancy processes and changing terms and conditions.

Debbie is renowned for her exceptional client care skills, forensic attention to detail and is a highly respected advocate. She is consistently ranked as a Band 1 Barrister by both Legal 500 & Chambers UK and is actively involved with the key employment law professional groups and associations. Debbie is on the Equality & Human Rights Commission (EHRC) panel of approved barristers.

Featured Employment & Discrimination cases


Sweeney v Merseyside Community Rehabilitation Company UKEAT/0277/17

A very lengthy appeal process concerning the admissibility of evidence and the impact of a reconsideration judgement by the Employment Tribunal (ET).


Concerning the Definition of Disability for Equality Act purposes and in particular, the tribunal’s approach to the term “likely” when considering whether the condition was long-term.


Callendar v South London & Maudsley NHS Foundation Trust UKEAT/0012/18

Dealing with the final straw in constructive dismissal claims and the tribunal’s approach to the proportionality defence in the Disability Discrimination claim.


McDowell v BAE Systems (Operations) Ltd [2018] ICR 214

Concerning the prima facie age-discriminatory tapering cap on BAE’s discretionary redundancy scheme and the extent to which this was justified.


Gallop v Newport City Council (No 2) [2016] IRLR 395 (EAT)

Dealing with knowledge of disability and the mindset of the decision-maker.


Gallop v Newport City Council [2014] IRLR 211 (COURT OF APPEAL)

Dealing with the requirement of knowledge of disability and the significance of Occupational Health advice.


Gallop v Newport City Council [2013] IRLR 23 (EAT)

Concerning the requirement of knowledge of disability and 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 & Immigration status.


Somerset County Council v Chaloner UKEAT/0600/12

Dealing with the correct approach to redundancy dismissals in the context of a business reorganisation.


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.

Debbie regularly undertakes internal investigation processes for employer clients (such as disciplinary, grievance, whistleblowing and Health & Safety matters), as well as chairing and determining issues at internal hearings and appeals.

She is also able to provide specialist employment advice in respect of their processes and decisions.

For employees, Debbie has particular expertise in cases which involve potentially career-ending allegations, most notably for senior medical staff, headteachers and legal and FCA-governed professionals.

Debbie regularly undertakes work in respect of proceedings before professional regulators. Her work includes advising and appearing in proceedings before the General Medical Council, the General Dental Council, the General Optical Council, the Nursing & Midwifery Council and the Teachers` Regulation Agency.

She also advises as to Solicitors’ professional conduct obligations under the Code of Conduct and in proceedings before the Solicitors Regulation Authority (SRA).

Debbie is exceptionally highly regarded for her employment law expertise. However, a significant part of her practice is in conducting independent investigations. In this area, she can fully utilise her pragmatic and user-friendly approach, exceptional witness handling skills, forensic attention to detail, ability to critically analyse the evidence and prepare the highest quality, fully reasoned written reports.

Debbie has extensive experience in this area across a range of sectors including healthcare, education, legal and finance, in both the public and private sectors. She is familiar with regulatory frameworks, and it is not unusual for her investigations to coincide with proceedings before a professional regulator or in some cases, to lead to such referrals.

The subject matter of Debbie’s recent instructions has included the following:

  • Investigations into the practice of consultant surgeons and other senior healthcare professionals, relating to both patient safety (eg. treatment decisions and surgical competence) and the treatment of other clinicians and support staff)
  • Investigation into alleged fraud and falsification of documents in the Education sector
  • Investigation into complaints of institutional racism within a Multi-Academy Trust, including the racial profiling of black students
  • Investigation into allegations of racism against multiple members of a clinical team in an NHS Hospital
  • Investigation into alleged breaches of the FCA regulatory framework by a regulated finance professional
  • Investigation into the failures of directors to declare conflicts of interest and/or to comply with establish procurement procedures when awarding contracts to third parties
  • Investigation into alleged historic and continuing sexual harassment of females by a male colleague
  • Investigation on behalf of a charity as to concerns about the professional probity and conduct of its in-house counsel.

On occasion, Debbie has been asked to present her findings to internal disciplinary and other hearings and has received accolades from all sides for the scrupulous levels of probity, fairness and impartiality she has demonstrated.

Debbie is one of the very few barristers recommended by Chambers and Partners in its new “independent investigations” practice area.

For enquiries please contact

Caroline Evans
Senior Practice Manager - Civil
0117 930 9000
Click here to email

Rob McDonald
Practice Manager - Employment, Costs & Litigation Funding
0117 930 9000
Click here to email

Charlie Georgeson
Assistant Practice Manager - Personal Injury, Clinical Negligence, Employment & Discrimination, Court of Protection (Health & Welfare), Costs & Litigation Funding
0117 930 9000
Click here to email

"Debbie is absolutely top notch and the full package: calm, collected, polished, well prepped and superbly knowledgeable, and her advocacy is a delight to watch."


Chambers & Partners 2025

‘Debbie is simply superb – pragmatic, personable, knowledgeable, painstaking and to the point. She puts clients at ease and engenders complete confidence.’


Legal 500 UK 2023

"She is knowledgeable, pragmatic and clear-thinking, with superb advocacy skills."


Chambers & Partners UK 2023

"Debbie's courtroom skills are exceptional. She is crystal clear on paper and in person, and always puts the client at ease."


Legal 500 2021

"A fantastic advocate and very client-friendly. She engages with the client and is able to distil complex factual and legal issues in layman's terms. She is calm and collected and gets the best out of witnesses. You definitely want her acting for your side!"


Chambers UK 2021

"She's tremendous, she's very strong, very diligent and very sensible."


Chambers UK 2019

"She's a very effective presenter, a feisty cross-examiner and a robust advocate."


Chambers UK 2016

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


Who's Who - Legal Bar 2015

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

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

For help or advice please call 0117 930 9000 or complete the form below.

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