The coalition led by Liam Cosgrave deserves "close scrutiny" for its response to the arrest of British special forces in the Republic in 1976, Sinn Féin says.
Louth TD Arthur Morgan made the claim after revelations the British government of the day had considered drastic measures against Dublin if the eight SAS soldiers were not freed.
The heavily armed soldiers were arrested just south of the Border. They claimed they were testing a car and had misread a map. They faced a host of weapons charges.
However, secret British government documents, published yesterday in the Irish News, reveal that London considered a range of penalties against Irish citizens in Britain and against Dublin unless the soldiers were freed.
Mr Morgan said the revelations raised fundamental questions about the government's response. "At least four people were murdered in mysterious circumstances in the Border area . . . Nobody was ever charged with these killings, although loyalists or elements of the British state were always suspected." He accused the Irish government of the day of being willing to "play along with Downing Street".