Four senior MPs have vowed to fight on after Tony Blair rejected calls to clear the names of the pilots blamed for the 1994 Chinook helicopter crash.
The crash on the Mull of Kintyre killed 29 people
They had asked the prime minister to re-examine the circumstances of the accident on the Mull of Kintyre.
Two air marshals found Flt Lts Jonathan Tapper and Richard Cook guilty of "gross negligence" after the crash.
Mr Blair told the MPs there was no new evidence which would persuade the Ministry of Defence to change its view.
In a letter, the prime minister said that the MoD had studied very carefully the report of a House of Lords committee chaired by Lord Jauncey, which was published in 2002.
It cleared the two men of blame in the crash, but its findings were not accepted by the government.
Mr Blair told the MPs that "as far as we are concerned there is no new evidence" and that no change should be made to the MoD's position.
Liberal Democrat defence spokesman Sir Menzies Campbell, one of the MPs who lobbied Mr Blair, said the prime minister had stuck to the government's previous approach.
"The four of us are not satisfied with this and as far as we are concerned the campaign goes on," he said.
"We feel that an injustice has been done and that is why we keep pressing the case."
Sir Menzies Campbell said an injustice had been done
The 29 people who died when the Chinook came down en route from Belfast to Inverness included 25 senior intelligence officers from Northern Ireland.
An RAF board of inquiry found nothing to indicate clearly what caused the accident.
However, two air marshals overturned that verdict and found Flt Lt Tapper, 30, from Burnham Thorpe in Norfolk, and Flt Lt Cook, 28, from Church Crookham, Hants, guilty of ''gross negligence''.
Subsequent investigations raised concerns about the airworthiness of the Chinook and a fatal accident inquiry was also unable to determine the cause of the crash.
A long-running campaign to clear the pilots has been backed by their families, the Church of Scotland and politicians such as former Prime Minister John Major.
The men's case also found support from a House of Lords committee chaired by Lord Jauncey when it concluded there was no justification for finding fault with the pilots.
Earlier this year the group of four senior MPs - Sir Menzies, former Conservative defence minister James Arbuthnott, Labour MP Martin O'Neill and David Davis, the shadow home secretary - met Mr Blair to press the case.
Sir Menzies said there was "nothing sinister" in the prime minister's refusal to change the government's stance.
"I think there is an inevitable inhibition against changing decisions which at the time were thought to have been taken in good faith and on the basis of what was known at the time.
"But when you have a senior judge like Lord Jauncey and a fatal accident inquiry here in Scotland under Sheriff Sir Stephen Young declining to accept the Ministry of Defence point of view as to how this accident happened, then it seems to me that politicians should pause, stop and consider changing their decision," he said.