An appeal against a ruling that Prime Minister David Cameron acted lawfully in refusing to hold a public inquiry into the murder of Belfast solicitor Pat Finucane will be heard in April.
Senior judges have set aside three days for the bid by the victim's widow to overturn a High Court verdict that the British Government was justified in reneging on a commitment to set up such a tribunal.
Mr Finucane was gunned down by loyalist paramilitaries in front of his wife and three children at their north Belfast home in February 1989.
His family have campaigned for a full examination of alleged security force collusion with the killers.
The solicitor's widow, Geraldine Finucane, took the Prime Minister to court after he ruled out a public inquiry in 2011.
Mr Cameron had instead commissioned QC Sir Desmond de Silva to review all documents relating to the case and produce a narrative of what happened.
Sir Desmond's report confirmed agents of the state were involved in the murder and that it should have been prevented.
However, it concluded there had been no overarching state conspiracy.
The Finucane family rejected the findings as a whitewash and accused the government of unlawfully reneging on previous commitments.
Pledges to set up such a tribunal, based on the recommendation of retired Canadian judge Peter Cory, were made by a former Labour government in 2004 and reaffirmed in the following years, it was contended.
Earlier this year a High Court judge ruled that Mr Cameron acted lawfully in refusing to hold a public inquiry.
He found that Mrs Finucane had received a clear and unambiguous promise that an inquiry would take place.
But he backed the government's case that other public interest issues, including political developments in Northern Ireland and the potential financial pressures of a costly inquiry, were enough to frustrate her expectation.
Despite throwing out Mrs Finucane's bid to force the authorities to publicly examine her husband's killing, the judge also said the State has not fully met its human rights obligation to investigate.
The family have refused to accept defeat in their legal battle, insisting a full independent and international tribunal of inquiry remains the only model capable of getting to the truth.
They claim internal communications shows former Secretary of State Owen Paterson carried out a "sham exercise" having already "closed his mind" to the type of inquiry previously promised.
Now the case is to go before the Court of Appeal for a further hearing.
At a review hearing today Lord Chief Justice Sir Declan Morgan fixed the challenge for a three days, beginning on April 25.