An Irish man accused of murdering four soldiers in an IRA bomb attack in Hyde Park in 1982 can be extradited to Northern Ireland to face charges over a separate bomb attack in 1972, a Dubin court has ruled.

The high court on Friday rejected John Downey’s attempt to avoid extradition, clearing the way for the alleged bomber to face trial in Belfast for the murder of two soldiers from the Ulster Defence Regiment a decade before the London bombing.

L/Cpl Alfred Johnston, 32, and Pte James Eames, 33, died when an IRA bomb exploded in a car they were checking in Enniskillen, County Fermanagh, on 25 August 1972.

Downey , 67, was detained at his home in County Donegal, in the Irish Republic, last November under a European extradition warrant.

Senior Sinn Féin figures protested against the prosecution, saying Downey had contributed to the peace process. Unionists said they welcomed it as overdue justice.

Downey’s Old Bailey trial for the Hyde Park murders collapsed in February 2014 because of a secret letter from the British government that guaranteed he would not face trial, a revelation that caused uproar.

Downey was one of 187 IRA suspects given “clear and unequivocal assurance” that they were no longer wanted by any police force in the UK, a concession by the British government to secure an IRA promise to decommission its arms as part of the 1998 Good Friday peace deal.

Downey had pleaded not guilty to the murder of four soldiers from the Household Cavalry who died in the blast on 20 July 1982, along with seven of their horses. The bomb had been concealed in a car and was detonated as the soldiers rode past on ceremonial duties.

The Police Service of Northern Ireland reopened an investigation into the Enniskillen attack after the collapse of the Old Bailey trial.