A judge will deliver his ruling on Thursday on legal challenges in Northern Ireland to a no-deal Brexit, he has confirmed.
Lord Justice McCloskey announced the timing for his decision in what he described as "complex and fast-moving proceedings" as a victims campaigner mounting one of the actions vowed to take his fight all the way to the Supreme Court.
Raymond McCord said: "The people of Northern Ireland must be represented at the highest court in the land. I'm prepared to go to London because of what's at stake."
Mr McCord's case is one of three cases fast-tracked and heard in Belfast over any attempt to take the UK out of the EU without an agreement.
The challenges centre on claims that any such departure by Prime Minister Boris Johnson and his Government would breach the Good Friday Agreement and threaten the peace process.
Reserving judgment after two days of arguments at the High Court, Lord Justice McCloskey set out plans to deliver a verdict in time for the judicial reviews to join up with Brexit actions brought in England and Scotland.
"I'm grateful to all counsel for their assistance in these complex and fast-moving proceedings," he said.
"Given that the Supreme Court has allocated 17 September with a view to hearing joint appeals in the Scottish case, in the English case, and this group of cases in Northern Ireland, and on the assumption that the relevant procedural requirements for reaching that elevated forum are satisfied, I will provide the reserved judgment of the court on Thursday morning."
It also provides a tight time frame for the Court of Appeal to hear the Belfast challenges before they are expected to progress on to London.
Despite suggestions that appeal judges could even sit on Saturday due to the urgency involved, legal sources pointed to Friday as a more likely date for the next stage in the legal process.
Mr McCord, whose son Raymond Jr was murdered by loyalist paramilitaries in 1997, alleges that a no-deal Brexit will plunge Northern Ireland into chaos and economic misery.
According to his legal team the Government are unlawfully trying to quit the EU without an agreement at any costs.
They claim that such an exit departure breaches the European Union (Withdrawal) Act 2018 which safeguards the 1998 Belfast Agreement.Counsel for the Prime Minister and UK Government argued, however, that the courts should not even be dealing with issues of foreign affairs and international relations.
It was also contended that Brexit laws impose no obligation on the UK to negotiate a withdrawal agreement with the EU.
Outside court, Mr McCord revealed he was discharged from hospital, where he had been receiving treatment for a serious medical problem, to ensure he could attend the conclusion of his case.
The campaigner also praised the judge for his handling of the case, saying: "He's been efficient and fast, probably setting a court record.
"I really believe now that Northern Ireland must be represented in the Supreme Court, we cannot be left behind and I will be there.
"This is about the people in Northern Ireland and the Republic of Ireland, this isn't a unionist or nationalist case."