British veterans and terrorists could be exempt from prosecution for alleged crimes in Northern Ireland during three decades of unrest under government plans to move away from the issues of the past.
The development came after a historic murder trial involving two former soldiers collapsed this week owing to a lack of evidence.
Following that decision, UK ministers are considering introducing a statute of limitations so no one can be charged over incidents before the 1998 Good Friday agreement, The Times newspaper reported.
An exemption will be made for cases involving war crimes, genocide or torture.
Irish Foreign Minister Simon Coveney strongly advised London "against any unilateral action on such sensitive issue".
Deputy First Minister Michelle O'Neill, whose Sinn Fein party heads up Northern Ireland's devolved power-sharing government with their former pro-Britain foes, also said a ban on prosecutions would be "a cynical move that will put British forces beyond the law".
She added that such a move would be "another slap in the face to victims".
Former military leaders had called for an end to the prosecution of those who served in an era, known as The Troubles, when armed troops patrolled streets of the British-ruled province riven by fierce sectarian conflict.
Ministers are to decide whether a “truth and reconciliation” process – used in post-apartheid South Africa – could be implemented instead. Under that system, people on both sides of conflict are encouraged to come forward and speak about the events of the past without fear of prosecution.
It is understood the aim of the reform is to shift the debate from a criminal one to a historical one.
Any move to introduce a statute of limitations will be outlined in the Queen’s Speech next week. The proposal has not yet been signed off by ministers.
On Tuesday, two veterans – identified in a court order as Soldier A and Soldier C – were cleared of the 1972 shooting of Official IRA member Joe McCann.
The judge ruled that statements the men gave to Royal Military Police hours after the shooting were inadmissible owing to several deficiencies – including that the soldiers were ordered to provide them and were not given legal representation.
Lawyers for veterans believe that a number of future cases in the province are now in jeopardy because they rely on interviews British soldiers were forced to give at the time.
Johnny Mercer, a former government minister who resigned over the treatment of veterans in Northern Ireland, said the prosecutions “should never have happened”.
“Hopefully this marks the lowest point in this nation’s treatment of her veterans,” he said. “Government must act.”
A separate trial of a soldier accused of murdering 13 unarmed Catholic civil rights marchers in Londonderry in 1972, when British paratroopers opened fire on the group on what became known as on "Bloody Sunday", is ongoing.