The Taoiseach says he continues to raise the Monaghan bombing with the British Government at every opportunity.
In May 1974, 34 people were killed in four explosions - three in Dublin City and one in Monaghan town.
No one has ever been convicted for what was the single greatest loss of life during the Troubles, with families of victims campaigning for years for the British Government to release all records they hold.
In the Dail, Sinn Fein's Matt Carthy asked when the Taoiseach last raised the issue with Boris Johnson, adding that it should be raised in every conversation with a British Prime Minister.
Micheal Martin says he remains committed to getting answers: