Where a decision-maker's decision is strongly influenced by someone acting with discriminatory motives, the decision may be viewed as a joint decision and may be discriminatory

In Commissioner of Police of the Metropolis v Denby the EAT upheld a Tribunal's decision that individuals who had heavily influenced the decisions of an official decision-maker should properly be regarded as joint-decision makers. That being the case, the motivations of all the joint decision-makers could be taken into account to determine whether the decisions were tainted by discrimination.  In this case, the influencers were acting from discriminatory motives, meaning the decisions were discriminatory.

Background law

When considering discrimination claims, Employment Tribunals must assess what are the grounds for the treatment in question. Where the act itself is not inherently discriminatory, it can be rendered discriminatory by the conscious or unconscious motivations which led to the act.

In CLFIS (UK) Ltd v Reynolds the claimant alleged that the termination of her consultancy agreement was discriminatory on the grounds of age. The Employment Tribunal (ET) dismissed the claim on the basis that the decision-maker's decision was not tainted by age discrimination. This was overturned by Employment Appeal Tribunal (EAT), which held that the ET was wrong to focus only on the mental processes of the decision-maker in circumstances where it was common ground that other individuals had significantly influenced the decision. However, the Court of Appeal restored the ET's decision and held that the correct approach is to consider distinct acts separately. Importantly, the Court said: "Supplying information or opinions which are used for the purpose of a decision by someone else does not constitute participation in that decision".

The "separate acts" approach endorsed by the Court of Appeal in CLFIS meant that claimants would need to plead each alleged discriminatory act separately, rather than asking an ET to take a "composite" view of all the actions in the chain of causation. On the other hand, where decisions were made jointly the ET would be able to assess the motives of all parties involved in that decision. A discriminatory motive by a co-decision maker would be enough to taint the overall decision.

In this case, the EAT had to consider whether a decision which had been taken by a decision-maker who had been heavily influenced by an individual acting with discriminatory motives should be treated as a joint decision, meaning that it would be a discriminatory decision.


Chief Inspector Denby (Denby), a man, was the head of TSG1, one of five branches of the Territorial Support Group (TSG). Chief Inspector Edwards (Edwards), a woman, was the head of TSG3, another branch of TSG. The under-representation of women within TSG was a concern.

Denby brought a discrimination claim alleging that he had been treated less favourably on the grounds of sex in relation to various matters, including:

  • He was treated differently to Edwards following allegations of false overtime claims: in TSG1, this led to a formal investigation and a spot check from Deputy Assistant Commissioner de Brunner (de Brunner), a woman. De Brunner was dismayed that Denby had, in her view, allowed a negative, male-dominated culture to fester within TSG1. She fed back her views to a more senior officer, Commander Musker (Musker), who, in turn, told the disciplinary decision-maker, DCI Sumner. This ultimately led to a disciplinary notice being served on Denby and meant he was placed on restricted duties. By contrast, in TSG3, there was no formal investigation and no disciplinary notice was served on Edwards.
  • He was treated differently to Edwards in performance assessments: a new performance assessment scheme was introduced, which determined prospects for promotion. Musker marked down the grade achieved by Denby, but did not mark down the grade achieved by Edwards.
  • His return to full duties was blocked: Musker eventually agreed to lift the restrictions on Denby's duties, however, this was blocked by another senior officer, Assistant Commissioner Gallan (Gallan).


During the Employment Tribunal hearing Musker admitted his involvement in some of the decisions that had been made. The Tribunal allowed Denby to amend his claim at a late stage to reflect Musker's decision-making role. The Tribunal went on to uphold Denby's claims, finding that de Brunner and Musker had influenced the decisions affecting Denby and that they had acted from discriminatory motives.

The Police Service appealed to the EAT, arguing that the decision-makers acted alone and the motives of others who sought to influence the decisions should be disregarded.

The EAT rejected the appeal.

  • They found that in relation to the overtime allegations and the actions that flowed from that, the decision-maker, DCI Sumner, had been so heavily influenced by de Brunner and Musker that it really amounted to a joint decision and it was tainted by discrimination.
  • They made a similar finding in relation to the blocking of Denby's return to full duties. Here, they found that Gallan had heavily influenced Musker and that, again, it really amounted to a joint decision tainted by discrimination.
  • As far as the performance assessment issue was concerned, they found that Musker had been influenced by de Brunner, but his decision to downgrade Denby's grade was a sole decision. However, it was still tainted by discrimination.


The EAT noted that the CLFIS decision needed careful handling. In particular, there was a danger that unscrupulous employers could use opaque decision-making processes as a means of hiding the presence of decision-makers acting from discriminatory motives. To address this risk, decision-making processes should be scrutinised and anyone who has heavily influenced the official decision-maker should properly be regarded as a joint decision-maker. This means that their motivations can be taken into account and would be capable of tainting the overall decision. The EAT also noted that Tribunals can assist claimants on the receiving end of opaque decisions by allowing them to amend their claims to identify any hidden joint decision-makers once their involvement is exposed.

Employers should ensure that their decision-making processes are transparent and that those providing information or evidence to a decision maker do not stray into the territory of lobbying for a particular outcome. This should ensure that only the motivations of the official decision-maker will be taken into account when assessing whether the decision in question was discriminatory.

Commissioner of Police of the Metropolis v Denby