The anti-LGBT Christian Institute has thanked gay activist Peter Tatchell for his support.

The owners of Ashers Bakery in Belfast are appealing a charge of unlawful discrimination, after the company refused to bake a cake showing the message ‘Support Gay Marriage’ above an image of Sesame Street’s Bert and Ernie.

The bakery owners are pursuing a legal challenge with financial and legal help from the Christian Institute – an anti-LGBT lobbying group which opposed the Equality Act and remains fundamentally opposed to anti-discrimination protections for LGBT people.

However, they found an unlikely ally in veteran gay activist Peter Tatchell, who has voiced support for the bakers on ‘free speech’ grounds.

After Mr Tatchell’s comments, a petition in favour of the bakers on the Christian Institute website surged to 15,000 signatures.

Simon Calvert of the Christian Institute has today thanked everyone who has voiced support for the bakers, ahead of the case’s hearing tomorrow.

According to the Newsletter, he said: “It is heartening that support continues to pour in for the McArthur family and the stand they have taken. In excess of 15,000 people have now signed our petition backing them.

“Some have attempted to portray this case as a minor business dispute. But what is really at stake here are fundamental principles – free thought, free speech and freedom from coercion by the state.

“The court is going to hear arguments from the Attorney General on why he believes the laws used against the McArthurs may be flawed. We will be able to comment on his arguments after the hearing following discussions with our own legal team.”

Mr Tatchell told PinkNews: “I have consistently opposed the homophobia of Ashers Bakery and the Christian Institute.

“I oppose any and all discrimination against LGBT people but do not believe that anyone should be compelled by law to aid political messages with which they disagree. For example, I do not believe that gay bakers should be forced by law to decorate cakes with homophobic messages. “

He explained previously: “The court erred by ruling that [gay customer Gareth Lee] was discriminated against because of his sexual orientation and political opinions.

“His cake request was refused not because he was gay, but because of the message he asked for.

“There is no evidence that his sexuality was the reason Ashers declined his order. Despite this, Judge Isobel Brownlie said that refusing the pro-gay marriage slogan was unlawful indirect sexual orientation discrimination.

Mr Tatchell claimed the ruling set a “worrying precedent” by suggesting that “service providers are required to facilitate any ‘lawful’ message, even if they have a conscientious objection”.

In addition to opposing discrimination protections, the Christian Institute previously fought to oppose civil partnerships, same-sex marriage and equal age of consent for gay people – while it sought to keep a ban on the ‘promotion’ of sexuality in schools.