Will an employer who discriminates always breach the implied duty of mutual trust and confidence?

Not necessarily. Although in many, perhaps even most, discrimination claims, an employer discriminating unlawfully will also breach the implied duty of mutual trust and confidence, this is not always the case (Greenhof v Barnsley Metropolitan Borough Council [2006] IRLR 98). For example, in Amnesty International v Ahmed [2009] UKEAT/0447/08/ZT, human rights charity Amnesty did not breach the implied duty of trust and confidence when it decided not to offer a Sudanese employee a role based in Sudan because of her Sudanese nationality out of concern for her safety. Amnesty’s decision not to offer the role was direct race discrimination. However, to breach the implied duty of trust and confidence, the employer had to conduct itself without reasonable and proper cause in a manner likely to destroy or seriously damage the relationship. Since Amnesty acted out of serious and genuine safety concerns, Ms Ahmed was not entitled to regard the relationship of trust and confidence as destroyed or seriously damaged.