The Christian owners of a bakery who refused to make a cake with a pro-gay marriage message should not be forced to withdraw from areas of business for fear of being forced to say something they oppose, Northern Ireland's top law officer said.
Ashers stopped offering products with messages for a period following a number of "vexatious" requests but it is now business as usual, a barrister for the company said.
The McArthur family, who run Ashers, are seeking to overturn a court judgment which found they acted unlawfully by rejecting the order placed by gay rights activist Gareth Lee in 2014 based on their religious conviction that the slogan was sinful. Three senior judges have reserved their verdict after a four-day hearing at the Court of Appeal in Belfast.
Attorney General John Larkin QC said: "A person should not be forced, be it in news print or icing sugar, to be the mouthpiece of A's views where B's views are opposed to those of A."
The executive's senior legal advisor has been granted permission to take part in the appeal after arguing that sexual orientation regulations in Northern Ireland discriminate against those like the McArthurs who hold religious or political beliefs.
McArthur family barrister David Scoffield QC said they received a number of "vexatious" orders following publicity surrounding the judgment and had limited their service to birthday cakes. He admitted the temporary bar had meant "locking off" a chunk of business.
"If it becomes the easy thing to say is we only do birthday cakes and we are excluding services, that points to at least partial withdrawal from the marketplace," he said.
The attorney general said the legal argument centred on political expression.
"The problem lies in coerced expression," he said.
"We say it is a very great wrong to make someone say something which conflicts with religious beliefs.
"The constitutional law in Northern Ireland means [the bakery] should not have to withdraw from areas for fear of being forced to saying something from which they disagree."
He said to refuse to serve someone because they were gay was "ethically outrageous".
But he maintained that compelling someone to make a product with a message with which they disagreed, in this case endorsing gay marriage, was an entirely different prospect.
Mr Scoffield has sought to disassociate the action of his clients from the sexuality of Mr Lee. Counsel for the Equality Commission which took the case on behalf of the would-be customer has argued that there was direct discrimination against him.
Mr Scoffield argued that the family neither knew nor cared whether Mr Lee was gay or straight, it was the message and taking any role in reproducing it that they objected to.
"It was nothing to do with the customer's political opinion," he said.
"A customer with a different opinion who wanted the same cake would receive precisely the same response."
Lord Justice Ronnie Weatherup asked: "Is it not a belief that this conduct is sinful based on sexual orientation?
"Does that not look like a characteristic which is indissociable from sexual orientation?"
Ashers, a name with biblical connotations, has six branches in Northern Ireland.
The three judges, including Lord Chief Justice Sir Declan Morgan and Lord Justice Reg Weir, will deliver their judgment at a later date.
