An appeal by Christian bakers at the centre of the so-called "gay cake" discrimination battle has been adjourned for three months.
It follows a last minute intervention by Northern Ireland's top legal advisor John Larkin QC.
Last year Ashers Baking Company, run by the McArthur family, was found to have discriminated against a gay customer for refusing to bake a cake with a pro gay marriage slogan.
Two days had been set aside for the appeal but proceedings at Belfast's High Court were dramatically halted after it emerged the region's Attorney General wanted to address any potential conflict between the local equality legislation and European human rights laws.
Northern Ireland's Lord Chief Justice Sir Declan Morgan, who was due to hear the high profile case with two other senior judges, expressed frustration but said the case could not go ahead at this stage.
He said: "It is most unfortunate this issue has arisen only two days before this hearing.
"Although we have all tried to see if we could proceed with the case given the amount of work that has been done.
"It seems to us that it is simply not possible to do that without running into some risk of fairness in the hearing.
"We are not going to proceed with the hearing today."
A lawyer representing Mr Larkin told the court the Attorney General wanted to address the "devolution issue" and to explore whether there were any incompatibility issues between the local laws and the UK's obligations under the Human Rights Act.
Adjourning the case until May, Sir Declan told the packed courtroom it was important that the case progressed to hearing "expeditiously".
The Northern Ireland Equality Commission, which monitors compliance with the region's anti-discrimination laws, took the landmark legal action on behalf of Gareth Lee, a gay rights activist and member of the LGBT advocacy group Queer Space.
It was heard at Belfast's County Court over three days last March.
Mr Lee had wanted a cake featuring Sesame Street puppets Bert and Ernie with the slogan Support Gay Marriage for a private function marking International Day Against Homophobia in May 2014.
He paid in full when placing the order at Ashers' Belfast branch, but two days later the company phoned to say it could not be processed.
District Judge Isobel Brownlie found Ashers directly discriminated against Mr Lee who had been treated "less favourably", contrary to the law and ordered them to pay agreed damages of £500.
Judge Brownlie said religious beliefs could not dictate the law.
At the appeal, Mr Lee sat in the front row of the public gallery of the Nisi Prius courtroom beside representatives of the Equality Commission.
Three rows behind were Ashers directors Karen and Colin McArthur with their son Daniel McArthur, the firm's general manager, and his wife Amy,
Simon Calvert from the Christian Institute, which has garnered public support and financial backing for the bakers, was also present as were Democratic Unionist MLAs Paul Givan and Edwin Poots, a former Stormont health minister.
The hearing, which lasted less than an hour, was dominated by complex legal argument around how the so-called "devolution issue" could be handled.
Robin Allen QC, representing the Equality Commission, said it was up to the court to decide whether to "salami slice" proceedings.
He added: "I dive into these waters with some degree of trepidation."
However, Sir Declan said there was a danger of "losing track" of the argument if the case was split in two with representation from the Attorney General being heard at a later stage.
He added: "We all have life jackets on."
Outside the court, Mr Calvert spoke on behalf of the McArthur family.
He said: "The court has adjourned the hearing essentially because of the importance of the issues at stake. The Attorney General has raised some new issues. We were neutral as to whether those issues came in but the court wants to hear them.
"It just confirms that this is a really important case and the court and all the parties want to make sure all the issues are properly rehearsed in court and we will be back on May 9 to do that."
Meanwhile, Dr Michael Wardlow - chief commissioner with the Equality Commission, expressed disappointment at the delay.
He said: "We came here today for this very important case and we were looking forward to hearing the arguments.
"We are very disappointed that at this very late stage another argument has come in and that has to be resolved.
"The reality is it could take months."
The case has been adjourned until May 9.