Former Justice Minister Charlie Flanagan has demanded MI5-trained bombers be prosecuted for the worst atrocity of the Troubles.
He says it is unacceptable no one has been charged for the 1974 attacks in Dublin and Monaghan which left 33 people – including an unborn child – dead.
The Fine Gael politician used his terms as Minister for Foreign Affairs and Justice to try to get answers from the British government but all to no avail.
He said: “It is wrong victims and their families are going to their graves not knowing the truth. They have a right to know who was responsible.
“This is one of the biggest legacy issues of the Troubles and it is really important that it is dealt with.”
Deputy Flanagan said the truth lies in secret files held by the British authorities.

Successive Irish Governments have demanded they be handed over but the British refused to cooperate.
He personally reached out to a number of secretaries of state in the North but got nowhere.
Similar requests were made by Justice Henry Barron in his 2004 Irish public inquiry into the bombings and he too was snubbed by London.
Mr Flanagan said: “We need these outstanding documents and files from the British so the truth can come out.
“For the victims’ sake I hope we get justice. After 46 years we haven’t conclusively established what happened that day and who did it. We need our two governments to work together on this.”
The British Intelligence Service MI5 has long been suspected of masterminding the bombings and supplying the explosives to the UVF but the loyalist terror group didn’t claim responsibility until 1993.
The Government believes it was effectively a state- sponsored attack but accept the actual British government at the time was not aware of it.
There were no public warnings and all four car bombs exploded indiscriminately causing carnage.
Three devices blew up in Dublin at rush hour in two-minute intervals at Talbot Street, Parnell Street and South Leinster Street, leaving 27 dead.
The bomb in Monaghan town detonated at 6.59pm, 90 minutes after Dublin, killing seven people.
Deputy Flanagan added; “I have had many meetings with the families. They need answers and soon.”