The Northern Ireland Troubles (Legacy and Reconciliation) Act 2023, which the Irish government is challenging in a rare interstate application to the European Court of Human Rights, ended most legal proceedings linked to legacy cases.

It established a new Independent Commission for Reconciliation and Information Recovery (ICRIR), headed by former lord chief justice Sir Declan Morgan, to instead carry out what the UK government insisted would be more “robust and effective” investigations into Troubles-related cases.

ICRIR was originally also intended to have the controversial power to offer immunity in some circumstances to those who co-operate with it, though this part of the Act was disapplied following a ruling by the High Court in February this year.

Labour, which is leading in the polls ahead of next month’s UK general election, states in its manifesto: “The Legacy Act denies justice to the families and victims of the Troubles. Labour will repeal and replace it, by returning to the principles of the Stormont House Agreement, and seeking support from all communities in Northern Ireland.”

Hilary Benn, the shadow secretary of state for Northern Ireland, told UTV: “We want to do that as quickly as possible.

“The Legacy Act has no support from victims’ families, no support from political parties in Northern Ireland and Keir Starmer gave the commitment that we would repeal and replace it and we are determined to do that to restore inquests, to restore civil cases, to get rid of immunity that many people object to.

“In the end after so many years families deserve to find out what happened and we want to go back to the principles of the Stormont House Agreement. We need to consult, because we want to get as much support as we can, as supposed to the current act which has basically no support at all.”