The Atomic Weapons Establishment has been accused of trying to stop a defence minister seeing 150 documents about blood tests taken from British troops during radiation experiments.
Prime Minister Rishi Sunak is now under pressure to intervene, and is facing calls from within his own party to back his minister over the civil servants who appear to be blocking him.
The records could finally prove the claims of veterans who say they were irradiated during Cold War weapons tests, with fatal and life-altering consequences.
But no-one is allowed access to them, as they are stored with other nuclear state secrets on a database accessible to only seven officials at the Atomic Weapons Establishment in Aldermaston, Berkshire.
In a Commons debate held in November, junior defence minister Andrew Murrison made a public vow to review 150 of the Top Secret files whose existence was denied for decades, until they were uncovered by the Mirror last year.
Michelle Mone's husband gifted Tories 'over £171k' as Covid PPE row rumbles onHe called the records - which also refer to the medical examinations of civilians and indigenous people whose land was used for nuclear blasts in Australia - “tantalising”, and promised survivors he would publish as many as possible.
The files have titles such as "report on medical examinations of natives" and "blood testing at Maralinga". The AWE has withheld the majority of them from the National Archives, has refused requests to publish others under Freedom of Information laws, and recently claimed to have no record of what grounds or legal processes were used to withhold them.
Murrison told the Commons: "It seems to me reasonable, given the level of public interest, to ask why these documents so tantalisingly put before us are not in the public domain in their entirety... If it’s merely sheets and sheets and sheets of dosimetry and urine and blood test results, I cannot see why it should not be."
But now he has been blocked by the AWE - extraordinarily, an agency of the Ministry of Defence where he is a minister.
A government source said: “Andrew has taken a lot of flak from the nuke vets, but he’s a decent guy and when he realised these records existed he knew many probably could and should be published.
“He asked the AWE for all 150 files, plus background papers, to review them personally. But they took ages and all they sent him was a few bits of paper they’d cherry-picked out of that pile he asked for.
"He kicked it back to them, and is determined to do what he promised. Politicians are elected to serve the people, and as a veteran and former medic he knows full well how important blood tests are for accurate diagnosis and treatment."
In public, Dr Murrison has refused to give a date for his review to be completed, but Labour MPs have questioned whether he has the right security clearance to view the files, which are kept separately to other AWE records on a database known as Merlin.
But Murrison believes that, as minister, he has every right to see the files and needs no extra security checks to do so. He told Parliament: "As the Minister responsible in the MoD for veterans' affairs, I retain the relevant clearances to view the information retained on Merlin."
But forcing the AWE to comply could mean getting Prime Ministerial approval.
500 deaths is criminal and you can't blame it on strikers - Voice of the MirrorThe source added: “If the minister keeps asking and AWE keeps saying no, only the Prime Minister can make the call. It boils down to whether Rishi Sunk wants these files opened or not. He may soon find there are a number of calls in Parliament, and within his own party, for him to back his minister.”
When running for the Tory leadership Sunak backed a police investigation into the veterans’ missing medical records. Since taking office, he has refused repeated requests to meet them.