Dozens of Tory MPs have reportedly written a letter to the British 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 UK 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.
Mrs May's official spokesman said he was not aware whether the Prime Minister has yet received the letter.
He added: "There is a consultation which has been taking place in relation to this issue. The purpose of the consultation was to allow everyone a say on the proposals in the 2014 Stormont House Agreement in relation to legacy and how we best move forward.
"Everyone deserves the opportunity to be heard. The Government is encouraged that so many people have responded to this important consultation.
"The Government will now consider all the views received and provide a response as soon as we can."
A total of 16,000 people have responded to the consultation, he said.
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.
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 power-sharing 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.
Conservative MP Richard Benyon, who served as an Army platoon commander in Northern Ireland in the 1980s, told BBC Radio 4's Today programme: "I think it's a burning injustice when people - many of whom have been investigated on more than one occasion and are now living in late old age - are being taken from their homes and being investigated.
"This is having a profound effect on today's armed forces as well.
"I think that over the years we have appeased the terrorists through the Good Friday Agreement, through the on-the-runs letters, through Royal pardons.
"Now (we have) old people like Dennis Hutchings - a terminally ill veteran in his late 70s - being taken to Northern Ireland.
"We've got others being taken before the coroners' courts for reasons that are inexplicable under judicial process."
Mark Thompson, whose brother was shot dead in Northern Ireland in 1990, told Today: "In the course of the conflict, the British Army were responsible for just under 400 killings.
"Four soldiers went to jail, all four were released significantly early in their sentences, two were sent on peace-keeping duties to Kosovo and the other two were promoted and got backdated pay.
"I think the indicative point is that when it comes to the British Army and the Tory Party, they want to talk about the rule of law when it's applied to everyone else but not to soldiers."