The Public Interest Disclosure Act 1998 (PIDA) creates two levels of protection for whistleblowers. The dismissal of an employee will be automatically unfair if the reason, or principal reason, for his/her dismissal is that he/she has made a "protected disclosure". PIDA also protects workers from being subjected to any detriment on the ground that they have made a protected disclosure. It is fairly common knowledge that the definition of "worker" under PIDA is wider than that under the ERA 1996. However, the recent case of McTigue v. University Hospital Bristol NHS Foundation Trust has highlighted just how widely the courts are willing to apply the definition.

Definition of "worker"

A "worker" is defined by section 230(3) ERA 1996 as: "an individual who has entered into or works under (or, where the employment has ceased, worked under) - 

  1. a contract of employment; or
  2. any other contract, whether express or implied and (if it is express) whether oral or in writing, whereby the individual undertakes to do or perform personally any work or services for another party to the contract whose status is not by virtue of the contract that of a client or customer of any profession or business undertaking carried on by the individual."

However, under section 43K ERA 1996, the usual definition of worker is extended in relation to the whistleblowing provisions to include a number of individuals who would not otherwise be covered. This extended definition includes agency workers and individuals supplied via an intermediary, provided that the terms of engagement are not substantially determined by the workers themselves but instead by the person for whom they work (section 43K(1)(a)(ii)).

Section 43K(2) ERA 1996 confirms that, for the purposes of section 43(1)(a), "employer" includes the person who "substantially determines or determined the terms on which he [or she] is or was engaged".

Facts of the case

The claimant was employed by an agency, Tascor Medical Services Limited (TMS Ltd), which assigned her to work at a sexual assault referral centre operated by the respondent trust. The claimant had a written contract of employment with TMS Ltd but she was also subject to the trust's standard form contract, which, among other things, identified the supervisor under whom she would work, set out an absence notification procedure, and required her to cooperate with the trust in relation to issues of health and safety, clinical governance, and working time. The contract also reserved the trust's right to terminate the contract in circumstances where the claimant acted in a way that might jeopardise the quality of patient care. However, as is usual in an agency relationship, TMS Ltd would operate all disciplinary and grievance procedures, and was responsible for the claimant's remuneration.

The claimant was removed from her assignment in December 2013, and brought detriment claims based on disclosures she had made to the trust. However, the employment judge at first instance found that the tribunal had no jurisdiction to hear the claimant's claim against the work, because she was not a worker under section 230(3) or 43K ERA 1996.

The judge focused on section 43K(1)(a)(ii), which he interpreted to mean, on the facts of the case, that the trust would have to determine the more significant terms on which the claimant worked for TMS Ltd if the claimant were to be a section 43K worker in relation to the trust. The claimant appealed to the EAT.

EAT decision

The EAT allowed the appeal, holding that the tribunal had erred in its approach to whether the claimant was a worker under the extended definition in section 43K(1)(a)(ii) ERA 1996. It remitted the case to a fresh tribunal.

In her judgment, Mrs Justice Simler, President of the EAT, began by setting out the proper interpretation of section 43K(1)(a). She observed that the provision focuses on identifying who, as between the individual and the other parties (the agency and the end user), substantially determines the relevant terms. A comparison between the agency and the end user is not necessary. Under section 43(K)(2)(a), the "employer" is the person who substantially determines the relevant terms, so it is possible that both the agency and the end user could be the employer for these purposes.

It is not necessary to consider who determined the majority of the terms, or the most significant terms, as between the agency and the end user. Where two parties (other than the individual) have between them determined the relevant terms, but have done so to different extents, both parties might have substantially determined the terms.

The trust made a submission that the extended definition of worker only applies to individuals who do not fit into the standard worker definition in relation to any partner. The EAT rejected this submission and held that the correct interpretation is that the extended definition is only engaged where any individual is not a standard worker in relation to the respondent in question. Accordingly, the fact that the claimant was a worker of TMS Ltd would not prevent her claiming section 43K protection with regard to the trust.


The decision is largely aligned with the reasoning in Day v. Lewisham NHS Trust and another UKEAT/0250/15, in which the EAT held that "substantially" in section 43K(1)(a)(ii) means "in large part". However, the cases follow a very different fact pattern.

The question in this case was not so much whether the claimant substantially determined her terms of engagement (it was not argued by the respondent that she did), but whether, where the terms of an agency worker's assignment are drawn from contracts with multiple parties, it is necessary to undertake an examination of which terms are derived from which party.

The EAT has confirmed that this exercise is not necessary for the purposes of section 43K(1)(a)(ii), although it may need to be carried out under section 43K(2), in order to work out who the relevant employer is. However, it should be noted that in some circumstances there may be two "employers" for these purposes.

Guidance on how to determine whether an individual is a worker within section 43K(1)(a)

In her judgment, Mrs Justice Simler helpfully set out a number of questions that should be addressed when determining whether an individual is a worker within section 43K(1)(a):

  1. For whom does or did the individual work?
  2. Is the individual a worker as defined by s.230(3) in relation to a person or persons for whom the individual worked? If so, there is no need to rely on s.43K in relation to that person. However, the fact that the individual is an s.230(3) worker in relation to one person does not prevent the individual from relying on s.43K in relation to another person, the respondent, for whom the individual also works.
  3. If the individual is not an s.230(3) worker in relation to the respondent for whom the individual works or worked, was the individual introduced/supplied to do the work by a third person, and, if so, by whom?
  4. If so, were the terms on which the individual was engaged to do the work determined by the individual? If the answer is yes, the individual is not a worker within s.43K(1)(a).
  5. If not, were the terms substantially determined (i) by the person for whom the individual works or (ii) by a third person or (iii) by both of them? If any of these is satisfied, the individual does fall within the subsection.
  6. In answering question (e) the starting point is the contract (or contracts) whose terms are being considered.
  7. There may be a contract between the individual and the agency, the individual and the end user and/or the agency and the end user that will have to be considered.
  8. In relation to all relevant contracts, terms may be in writing, oral or implied. It may be necessary to consider whether written terms reflect the reality of the relationship in practice.
  9. If the respondent alone (or with another person) substantially determined the terms on which the individual worked in practice (whether alone or with another person who is not the individual), then the respondent is the employer within s.43K(2)(a) for the purposes of the protected disclosure provisions. There may be two employers for these purposes under s.43K(2)(a).

Key takeaways from the case

The key takeaways from the case are that an agency worker may be able to bring a whistleblowing claim against an end user, provided that the terms of engagement are not substantially determined by the worker himself/herself; and that the fact that an individual may be a section 230(3) worker in relation to the agency does not automatically prevent that individual from being a worker under the extended definition in relation to the end user.