Boris Johnson’s plan to give Northern Ireland veterans a legal exemption from prosecution is to be unveiled this week, and will also protect republican paramilitaries, The Telegraph understands.

Brandon Lewis, the Northern Ireland Secretary, is preparing to set out proposals for a statute of limitations on prosecutions for crimes committed during the Troubles.

The new cap on historic prosecutions is expected to apply to combatants on both sides of the conflict.

Mr Lewis had pledged to deliver plans to Parliament before the summer recess, which begins on July 22.

Trials linked to the Troubles will be blocked as ministers move towards a “truth and reconciliation” approach, modelled on a similar policy used in post-apartheid South Africa, and will focus on reconciling communities in Northern Ireland rather than pursuing combatants.

It will also allow people who were involved in the conflict to testify about what happened without fear of prosecution, giving closure to families of those who were killed.

The decision follows the collapse of two trials of British paratroopers – known as Soldier A and Soldier C – in May, which saw key evidence ruled inadmissible by a judge.

It is thought that the length of time between alleged crimes of the Troubles era and trials brought today leaves prosecutors with limited evidence to push for a conviction.

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The statute of limitations will go further than measures announced in the Overseas Operations Bill earlier this year, which said Troubles veterans could still be prosecuted providing there was “new, compelling evidence” to present to a jury.

Johnny Mercer, a former defence minister, left the Government after the bill was presented to Parliament, claiming he had been forced to break a promise to veterans that they would not be pursued any longer in the courts.

At the time, he said veterans were “being sectioned, drinking themselves to death and dying well before their time, simply because the UK Government cannot find the moral strength or courage we asked of them in bringing peace to Northern Ireland in finding a political solution to stop these appalling injustices”.

A similar system of limitation already exists for veterans of the Iraq and Afghanistan wars, who will not be prosecuted after more than five years after an alleged offence, apart from torture, genocide and crimes against humanity.

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Mr Lewis’s proposals for Troubles prosecutions will be controversial in some quarters as they would also prevent prosecution of alleged crimes committed by members of the IRA and other paramilitary groups in the same period. However, writing in The Telegraph, Julian Lewis, the former chairman of the Commons defence committee, said the proposals “must apply to all sides – our service personnel, police, loyalists and nationalists alike”.

He insists: “This does not set law-breakers on the same level as the forces of law and order, any more than the fact that the Belfast/Good Friday Agreement and sentencing act which followed it – limiting prison sentences arising out of the Troubles – already does… It would be a clear and hard-headed assessment of where we actually are. I believe it would give individuals and Northern Ireland’s society, as a whole, the best opportunity of moving on from the past.”

Northern Ireland’s Public Prosecution Service said in 2019 that of its 32 “legacy cases” since 2012, 17 related to republicans, eight to loyalists, and five to the British Army.

Mr Lewis said the “exhaustive investigatory process” required to determine whether evidence is new or compelling “shifts the difficulties from one place to another” and could still result in veterans appearing in court.

Mr Johnson has already faced accusations he is dragging his feet on dealing with Troubles-era prosecutions, after suggestions of a new bill appeared in two successive Queen’s Speeches but never materialised in law.