Bertie Ahern has directly disputed Gerry Adams's claim never to have been in the IRA.
The Irish Prime Minister was maintaining an attack on Sinn Féin's credibility amid the continuing fallout from the attempted abduction of republican dissident Bobby Tohill.
Sinn Féin has accused Ahern and Fianna Fail of playing politics ahead of the June local and European election.
Mr Adams has always denied ever being a member of the IRA. Until recently, the IRA was a proscribed [illegal] organisation. A conviction on membership of the IRA resulted in a lengthy prison sentence.
Said Ahern: ``I always assumed that he was, to be frank with you. I'd be surprised if he wasn't, in one form, back over the years.''
In his remarks to reporters, Mr Ahern said he was ``not particularly interested'' in whether Mr Adams was or wasn't an IRA member at some stage in the past. ``I'm more interested in what's happening now. I think Gerry Adams and Martin McGuinness have a clear role to play,'' he said.
Mr Ahern rejected comments by Mr McGuinness that the controversy over the alleged abduction attempt in Belfast last Friday was part of a vendetta against Sinn Féin and the IRA by rogue elements of the British security forces.
He insisted that ``four fairly prominent IRA people kidnapped a man from a pub and beat him to a stage where he needed 93 stitches. It is generally believed that he was on his way to his death.''
He said it was necessary now ``to move away from that''. Mr McGuinness and Mr Adams had a role to play in this, he said.
In response, Mr Adams said simply: ``The Taoiseach's assumption is wrong.''
He said he was prepared to give the Taoiseach ``the benefit of the doubt'' but said some people believed he was working to an agenda to cause difficulty for Sinn Féin at the time of its ardfheis.
* Veteran republican John Kelly, a former Sinn Féin Assembly member and IRA Volunteer, said in a letter today he was ``disappointed and flabbergasted'' by Mr Adams's ``need to deny the IRA''.