EAT Decision in Dr. Sara Ajaz v Homerton University Hospital NHS Foundation Trust Emphasizes Limits on Subsequent Claims and Settlement Agreements

Citation: [2023] EAT 142
Judgment on


In the Employment Appeal Tribunal case of Dr Sara Ajaz v Homerton University Hospital NHS Foundation Trust [2023] EAT 142, several legal principles of employment law were at the forefront. The case centered around Dr. Ajaz’s claims of detriment as a result of making protected disclosures, the previous settlement of similar claims via a COT3 agreement, and the application of Rule 52 of the Employment Tribunals (Constitution and Rules of Procedure) Regulations 2013. This analysis aims to scrutinize the key topics and legal principles deliberated in the case.

Key Facts

Dr. Sara Ajaz brought claims against the Homerton University Hospital NHS Foundation Trust, asserting she had suffered detriments following protected disclosures made between 2011 and 2016. Having settled her 2017 Claim under a COT3 agreement, she withdrew her claim, leading to a dismissal by an Employment Judge. Dr. Ajaz remained employed and subsequently presented new claims in 2021 for detriments alleged to have occurred after the COT3 agreement, citing the same protected disclosures. The Employment Judge (EJ) struck out the 2021 Claims on the basis of Rule 52 and as an abuse of process.

The case considered the following legal principles:

  1. Rule 52 of the Employment Tribunals (Constitution and Rules of Procedure) Regulations 2013: It mandates dismissal of a withdrawn claim, preventing re-litigation of the “same, or substantially the same, complaint”, unless certain exceptions apply.

  2. ‘Res Judicata’ and its variants: The doctrines of cause of action estoppel, issue estoppel, and the principle in Henderson v Henderson were invoked to assert that Dr. Ajaz could not re-open the issues decided in the previous claim.

  3. Terms of the COT3 Agreement: The interpretation of various clauses in the agreement was pivotal in determining whether future claims could be compromised, especially clauses related to the settlement of claims and exclusions.

  4. Section 43J of the Employment Rights Act 1996: It addresses the void nature of agreements that preclude a worker from making a protected disclosure.

Each of these legal principles was examined critically, weighing against the background of existing case laws like Virgin Atlantic Airways Ltd v Zodiac Seats UK Ltd [2014] AC 160 and Johnson v Gore-Wood & Co [2002] 2 AC 1, among others.


The analysis led to the following outcomes:

  1. Rule 52 Application: The EAT found that Rule 52 did not give rise to estoppel in Dr. Ajaz’s circumstances and was considered narrower in scope than general powers to consider and apply res judicata.

  2. Issue Estoppel: The EAT concluded that the EJ’s analysis of issue estoppel was insufficiently explained and not necessarily applicable to the dismissal of the 2017 Claim.

  3. COT3 Agreement Interpretation: The EAT upheld the EJ’s interpretation that the 2021 Claims were an abuse of process due to the terms of the COT3, which prohibited relitigating settled issues.

  4. Section 43J of ERA: It was held that the EJ correctly determined that section 43J was not relevant, as the COT3 did not prevent the appellant from making protected disclosures but settled the previous dispute over whether she had done so.

  5. Potential Repudiatory Breach: Ground four of the appeal concerning a purported repudiatory breach of the COT3 was rejected. The EAT found no error in the EJ’s approach since the Appellant did not seek to resolve this issue or claim acceptance of an alleged breach at the preliminary stage.


The EAT’s decision in Dr. Sara Ajaz v Homerton University Hospital NHS Foundation Trust reaffirmed the stringent application of legal principles surrounding settlement agreements and the limitations on subsequent claims. Specifically, the case clarifies the constraints on relitigating settled issues and the interpretation of Rule 52 within the confines of the ET Rules. It also underscores the judicial discernment required when leveraging issue estoppel and the scope of agreements’ terms in relation to protected disclosures. Notably, while the EJ’s decision on the role of Rule 52 was set aside, the comprehensive interpretation of the settlement agreement and the principles of res judicata ultimately led to the dismissal of the appeal. This complex interplay of principles serves as valuable guidance for legal professionals navigating similar employment law landscapes.

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