Sinn Féin's Mr Caoimhghín Ó Caoláin has called for a Dáil debate on the 1974 Dublin and Monaghan bombings.
The calls comes after reports that Britain planned to claim sovereign immunity defence over allegations its secret service agents were involved in the attacks.
Mr Ó Caoláin said the new information was "virtually an admission of guilt" on the part of Britain and called for a debate on the matter to be held in the Irish Parliament this week.
He said: "We learn now that the British Government was preparing to invoke international law to protect itself from prosecution because of the actions of its agents. The same defence was used by the notorious Chilean dictator Pinochet". Reports in a weekend newspaper said leaked British Government documents suggested the British government would claim sovereign immunity if it faced litigation by bereaved relatives and victims of the attacks, in which 33 people died.
Other leaked documents indicated British officials explored how to defend claims against individual agents - but that if there was evidence against any agents, those individuals would be condemned and shunned by the authorities.
The documents have fuelled suspicions among survivors that British intelligence agents colluded with loyalist paramilitaries who planted the car bombs on May 17th, 1974.
PA