Dozens of Tory MPs have reportedly written a letter to the Prime Minister calling on her to drop plans to investigate Northern Ireland military veterans.
There has been outrage over potential legal action against soldiers for events linked to the Troubles.
A Government consultation paper, Addressing The Legacy Of Northern Ireland’s Past, was launched in May on how a historic investigation could be carried out.
In a letter to Theresa May, 150 Tory MPs and peers say a new Historical Investigations Unit would put “service and security personnel at an exceptional disadvantage”, the BBC is reporting.
In July, more than 30 Tory MPs supported a backbench proposal for a 20-year time limit on reopening cases involving former members of the armed forces who served in Northern Ireland.
And, earlier this month, a cross-party group of Westminster politicians, including four former Northern Ireland secretaries, urged Karen Bradley to draw a line under the region’s past.
Lord Hain and seven other signatories advised prioritising compensation for victims over investigation.
The past has been one of the sticking points between the Democratic Unionists and Sinn Fein through several rounds of failed talks to agree the return of powersharing at Stormont.
The pursuit of former soldiers has also sparked outrage among veterans, particularly following the arrest of pensioner Dennis Hutchings.
Mr Hutchings, a 77-year-old former member of the Life Guards regiment, is accused in relation to the fatal shooting of a man with learning difficulties in 1974.
The Daily Express reported on Monday that he is refusing treatment for kidney disease for fear it would get his case dismissed on medical grounds.
Mr Hutchings, from Cawsand in Cornwall, is due to stand trial in Belfast charged with attempted murder and attempted grievous bodily harm with intent. He denies the charges.
John Pat Cunningham, 27, was shot in the back in Co Armagh as he ran away from an Army patrol. His family argued that he ran across a field because he feared men in uniform.