Mr Gareth Lee, a homosexual man who is actively involved in the lesbian, gay, bisexual and transgender community, was planning to attend an event to mark the political momentum in Northern Ireland towards legislating for same-sex marriage. He ordered a cake from Ashers Baking Co Ltd, of which Mr and Mrs McArthur are directors, to be iced with a graphic and the caption "support gay marriage". Mr and Mrs McArthur felt that providing the cake would amount to promoting same-sex marriage, which was against their Christian beliefs, and that they could not do so in good conscience. They therefore refused to complete the order and Mr Lee bought a replacement cake from another supplier.

The County Court in Northern Ireland held that this refusal amounted to direct discrimination on the grounds of Mr Lee's sexual orientation under the 2006 Regulations. Dismissing Mr and Mrs McArthur's argument that they had not treated Mr Lee unfavourably because they would have supplied a different cake to Mr Lee, and would have refused a similar order from a heterosexual customer, the court held that the correct comparator would be a heterosexual customer placing an order with the slogan "support heterosexual marriage".

The bakery appealed. The appeal was adjourned following an intervention by the Attorney General of Northern Ireland in order to make representations in the case about the potential conflict between the anti-discrimination provisions in the 2006 Regulations and Article 9.

The Court of Appeal in Northern Ireland upheld the decision, although it found that the County Court had reached the right result for the wrong reasons. The court asserted that it was clearly wrong for the County Court to have held that support for same-sex marriage was indissociable from sexual orientation. Many heterosexual people support same-sex marriage and some homosexual people oppose same-sex marriage.

The court held that, correctly understood, the case was one of associative discrimination. Mr Lee had been discriminated against because of his association with the protected characteristic of sexual orientation. It held that there is an exact correspondence between those of the protected sexual orientation and those in respect of whom the message on the cake supported the right to marry. This relevant protected characteristic is shared by the homosexual and bisexual community at large, and Mr Lee was associated with this community. Therefore there was direct discrimination based on Mr Lee’s association with the homosexual and bisexual community.

Although this decision has been well-publicised, there is nothing particularly novel or extraordinary about it. The court applied the now well-established principle that the sincere religious beliefs of a service provider, as protected by Article 9, do not exempt that service provider from the legislative prohibition on direct discrimination on grounds of sexual orientation. The court noted that if businesses were free to choose what services to provide to the homosexual community on the basis of religious belief, the potential for arbitrary abuse would be substantial.

It is striking that Mr Lee pursued his claim as one of associative discrimination, particularly given that a court is likely to award a smaller injury to feelings award in such claims in comparison with cases where a claimant's own protected characteristic has resulted in the unlawful discrimination in question.

Associative discrimination claims typically arise where the claimant complains about less favourable treatment that he has experienced because of his association with a protected characteristic that he does not possess. Although a claim brought by a heterosexual man who sought to buy a cake supporting gay marriage might need to be brought as an associative discrimination claim, Mr Lee is homosexual: a fact that the County Court found was known or perceived by the bakery. If, as seems likely, the matter is next considered by the UK Supreme Court, it is likely to consider whether, properly analysed, this case is one of associative discrimination at all.

Paragraph 3.41 of the Equality and Human Rights Commission's Equality Act 2010 Statutory Code of Practice for Services, Public Functions and Associations states that service providers are more likely to be able to comply with their duties under the 2010 Act, and prevent their employees from discriminating against service users or customers, if they take the following steps: