The British government faced an angry backlash in Dublin and Belfast on Thursday after the leaking of its plans to cease the prosecution of those accused of violent crimes during the Northern Ireland Troubles.

UK ministers plan to introduce a statute of limitations to prevent charges for incidents that occurred before the 1998 Good Friday Agreement, with only a few exceptions such as genocide or torture, according to reports in The Times and Daily Telegraph on Wednesday night.

The bar on prosecutions would include former paramilitaries and security forces personnel who were active in the region during almost three decades of sectarian strife when republicans taking up arms for a united Ireland fought with security forces and loyalists who supported Northern Ireland’s place in the UK.

The UK government is also planning a “truth and reconciliation” process allowing those on all sides to discuss historical events without fear of prosecution.

One UK official told the Financial Times that no final decision had yet been made but both initiatives comprised the “direction of travel” for ministers. “We are more focused on truth and reconciliation than the pursuit of prosecution,” he said.

Politicians of all stripes on both sides of the Irish border reacted angrily to the reports, objecting to the unilateral nature of the UK’s move and voicing concerns that victims of past crimes would see the statute of limitations as an amnesty for those involved in a conflict that left more than 3,500 people dead.

Michelle O’Neill, the nationalist Sinn Féin deputy first minister for Northern Ireland, said the “not acceptable” proposal was “another slap in the face to victims. This is another cynical move that will put British forces beyond the law . . . a legal protection for those involved in state murder,” she said.

Northern Ireland’s biggest party, the Democratic Unionists, was also highly critical, with its East Belfast MP Gavin Robinson describing “access to justice” as “a vital principle . . . [that] should not be removed. We must be clear that if someone has committed murder, they should be prosecuted for that crime regardless of who they are,” he said.

The Ulster Unionist party’s justice spokesperson, Doug Beattie said the “de facto amnesty” was wrong because it would give “equivalence” between the forces of law and order and “self-appointed murderers”. “We must never forget that terrorists were responsible for 90 per cent of Troubles-related deaths, the security forces 10 per cent,” he added.

The 2014 Stormont House agreement included plans to set up a £150m unit to investigate all deaths during the Troubles but this will now be dropped.

The news comes just days after the collapse of the trial of two former paratroopers, known as Soldier A and Soldier C, who were accused of murdering an Official IRA commander in 1972.

Ireland’s foreign affairs ministry said the Dublin government had “strongly advised against any unilateral action on such sensitive issues. I’ve met many victims of the Troubles & their families,” foreign affairs minister Simon Coveney tweeted on Thursday morning. “I’ve seen ongoing heartbreak & pain whenever legacy is in [the] news. Victims and Northern Ireland must be the priority, the only priority.”

Coveney met Brandon Lewis, the Northern Ireland secretary, on Wednesday for talks on issues facing the region, but the Irish minister was not given advance warning of the UK government’s plans to introduce an amnesty, a person familiar with the meeting told the FT.

Sinn Féin MP John Finucane, the son of murdered solicitor Pat Finucane, said on Twitter: “The revelation that the British Govt intend to legislate so that British Army & RUC [the then-police force of Northern Ireland] killers of citizens here cannot be prosecuted shows that the lives of victims and their families mean nothing to the British Govt. It is an outright attack on the justice system and the rule of law.”

A spokesperson for the UK government said it had “clear objectives” for addressing the legacy of the Troubles and delivering manifesto commitments for Northern Ireland veterans.

The Conservatives’ 2019 election manifesto promised new legal protections to prevent military veterans being prosecuted over killings during the Troubles.

“It is clear to all that the current system for dealing with the legacy of the Troubles is not working for anyone, failing to bring satisfactory outcomes for families, placing a heavy burden on the criminal justice system, and leaving society in Northern Ireland hamstrung by its past,” the spokesperson said.