UK challenged over 1974 Dublin-Monaghan bombings
The Government has been urged to hand over documents on the 1974 Dublin-Monaghan bombings.
Some 33 people and an unborn child were killed in a series of co-ordinated bombs on May 17, 1974.
The UVF claimed responsibility in 1993 for the atrocity, which included three bombs in Dublin during the rush hour and a fourth in Monaghan 90 minutes later.
The dead ranged in age from five months to 80 years.
Fianna Fail TD Brendan Smith met with Secretary of State James Brokenshire and urged him to release the documentation relating to the bombings so that a full investigation can be carried out. Mr Smith raised the matter at the recent British-Irish Assembly in Wales.
"May 17, 1974, marked one of the darkest days in the legacy of the Troubles and, to date, the victims and the families of those who died have been left without a full and proper investigation into the atrocities," he claimed.
"Thirty-three were killed and almost 300 were injured in the Dublin-Monaghan bombings, and despite numerous calls for an investigation, the British Government has continuously refused to give its full co-operation.
"I met with Secretary of State Brokenshire and once again emphasised the importance of a full investigation into these attacks and urged him to release all of the documentation related to these terrible tragedies, so that the perpetrators of these atrocities can be brought to justice."
There have been claims of collusion between the security forces and the UVF.
Mr Smith said the victims and families of those who died deserve to know the truth.
"The release of these documents would help establish the facts of that dark day," he said.
"There is a responsibility on the British Government to assist in this investigation."