The Ashers bakery appeal case has been dramatically adjourned today following intervention by the Attorney General.
John Larkin QC's lawyer raised legal issues with the court regarding discrimination and equality legislation.
The Attorney General has made a last-minute request to make representation in the case about any potential conflict between the region's equality legislation and European human rights laws.
After a short hearing Lord Chief Justice Sir Declan Morgan agreed to adjourn the appeal until May 9 where it will sit for four days.
He told the court it was "most unfortunate this issue has only arisen two days before 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.Tweets by @DeborahMcAleese
"We are not going to proceed with the hearing today" he said.
Senior judges in Belfast decided to adjourn Ashers' challenge to the ruling after being told of issues about the lawfulness of sexual orientation regulations in Northern Ireland.
Before the hearing in May the Court of Appeal will sit again in March to hear legal arguments on the compatibility of the regulations with European human rights law.
They will also decide whether it raises a devolution point which opens the door for Attorney General John Larkin QC to become involved in the case.
Sir Declan said it was simply not possible to continue at this stage without risking any unfairness to the proceedings.
The Christian family run bakery is appealing the ruling of the high profile case which was heard over three days last March.
A judge at Belfast County Court said Ashers Bakery run by the McArthur family acted unlawfully by declining an order from gay rights activist Gareth Lee.
Mr Lee, a member of the LGBT advocacy group Queer Space, 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 said he was stunned when - two days later - the company phoned to say it could not be processed.
Ordering the bakers to pay agreed damages of £500, the judge said religious beliefs could not dictate the law.
Today the Equality Commission, which monitors compliance with the region's anti-discrimination laws, took the landmark legal action on behalf of Mr Lee, said it was "very disappointed" that the matter was not able to proceed.
Speaking outside the court ahead of today's hearing Daniel McArthur outlined his reasons for the appeal - saying they took issue with the "message on the cake and not the customer".
He said: "We are looking forward to having the ruling of the Lord Chief Justice overturned.
"We believe the County Court got the original ruling wrong.
"Ashers does not discriminate against anyone. We took issue with the message on the cake not the customer.
"And as a family we believe we should retain the freedom to decline business that would force us to promote a cause with which we disagree.
"As Christians we can't simply switch off our faith as we enter the workplace in the morning.
"To be a Christian at all is to strive to live for Christ in every corner of our lives."
"We served Mr Lee as we would any other customer we were simply unwilling to endorse this campaign for a new law that so clearly goes against what the bible said about marriage
"And for that we have been punished."
He added: "As Christians, we are law abiding citizens and we expect the law to protect us as much as anybody else.
"We hope that the judicial system will now make the correct decision and protect our freedom to carry out our work without being forced to violate our consciences.
"As a family we have found the whole process very difficult. We would rather not be here today. We knew we had to appeal not only for ourselves but on the behalf of other family businesses who could be forced to endorse or promote views with which they disagree,.
"Today we appeal to the Lord Chief Justice and colleagues to overturn the county court ruling, we appeal to them to recognise there is a big difference between refusing to serve someone because of their sexual orientation or political opinion and choosing not to endorse those ideas."
Outside of the courtroom Mr Lee has not spoken publicly about the case - he arrived at court accompanied by the Equality Commission's chief commissioner, Dr Michael Wardlow.
Dr Wardlow said it was not an attack on religious freedom.
He sad: "There has been a lot of misinformation in the media that somehow this is about closing down religious expression, that faith has to be left at the door of the workplace and that is not true.
"Religious freedom is enshrined in the legislation. The problem is although freedom to believe is absolute, freedom to express that belief is always limited, because if by expressing that belief you discriminate against others then the law must intervene.
"So this is not simply about some form of religious intolerance or closing down of Christian expression because in all of this the other person who has a right in this, who seems to have been forgotten, is Gareth.
"So I would like this to be seen for what it is - this is about if you enter into the public domain and choose to trade as a commercial enterprise you are ruled by the laws of the land."
During the hearing Mr Lee sat in the front row of the public gallery beside representatives of the Equality Commission.
Three rows behind were Ashers directors Karen and Colin McArthur with their son, the firm's general manager Daniel McArthur, and his wife Amy, plus Simon Calvert from the Christian Institute, which has garnered public support and financial backing for the bakers.
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 a number of 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."
Leading gay rights campaigner Peter Tatchell has come out in support of Ashers. Having claimed the original decision was a victory for equality, Mr Tatchell now concedes the law suit against the bakery was "a step too far".