Irish Labour Party leader Eamon Gilmore was a member of a group affiliated to Official Sinn Fein, the left wing republican organisation, during the 1970s.
Mr Gilmore was evasive on the subject at the weekend, and claimed in a high profile radio interview that he "subsequently joined the Workers' Party" after attending University College Galway. But he was unclear about whether he was a member of Official Sinn Fein (OSF).
He was accused by Taoiseach Brian Cowen yesterday of trying to "reinvent himself in trying to remember what party he joined when he left UCG".
"He could not remember whether it was Sinn Fein The Workers' Party or the Workers' Party," Mr Cowen said.
During an interview on the 'Marian Finucane Show' on RTE Radio at the weekend, Mr Gilmore was first asked if he was in Sinn Fein The Workers' Party or OSF. OSF became Sinn Fein The Workers' Party in 1977 and the Workers' Party in 1982.
Mr Gilmore claimed the party "was in the process of becoming the Workers' Party at that time, I can't recall exactly the dates". He was then pressed on whether the party was actually Official Sinn Fein. "Not at that time, I think," Mr Gilmore replied.
But Brian Hanley, one of the authors of 'The Lost Revolution: The Story of the Official IRA and the Workers' Party' said Mr Gilmore was in the Republican Club, the university wing of OSF, during his time in UCG, where he started in 1972.
"Official Sinn Fein didn't add the Workers' Party until 1977 and didn't change to the Workers' Party until 1982," Mr Hanley said. He said Mr Gilmore was known to be a member of the Republican Club in 1975, a full two years before it joined with the Workers' Party
"At that time, the Republican Club was part of Official Sinn Fein," Mr Hanley said. He said the Republican Club in the college sold the party newspaper, which regularly carried lists of IRA prisoners in jail.