Amnesty International has slammed the idea of a statute of limitations for all crimes committed during the Troubles as an "utter betrayal" of victims.
Speaking at meeting in Westminster on Thursday, Northern Ireland's attorney general, John Larkin QC, backed the implementation of a statute of limitations, as long as there is wider political support for it.
He also said a specialist judge should test whether Troubles-related crimes allegedly carried out by British soldiers should be prosecuted.
Mr Larkin stressed that law changes would be required if Prime Minister Boris Johnson wants to fulfill his commitment to stop prosecutions of former army personnel, the Times reports.
Without new legislation, Mr Larkin said such cases would "trundle on and on because we have no statute of limitations. If he wants to change the law, then he should do so; if not then we will remain as we are."
He said a "certification" system would be his preferred solution to the issue, whereby legacy allegations against former soldiers would be assessed by a senior judge before being put before the courts.
"If you had a case involving a soldier who was 19 at the time and took a decision in the heat of the moment the judge could take a view on whether it was in the public interest to prosecute," he said.
"Cases that were granted a certificate would proceed, those that were not would be dismissed."
Grainne Teggart, Amnesty International's Northern Ireland campaigns manager, said the UK government "must not legislate for impunity" through a statute of limitations.
“The effect of a statute of limitations would be to grant a blanket amnesty for human rights abuses committed by former members of the security forces," she said.
“To place perpetrators of crimes committed during the Troubles above the law would be an utter betrayal of victims’ fundamental right to justice.”
Veterans minister Johnny Mercer said he would introduce a bill next week to safeguard former soldiers from "vexatious legal claims".
Alliance Party MP Stephen Farry, however, challenged this narrative, stating it "undermines the criminal justice system which has the ability to weed out such claims".