The Taoiseach had a 15 minute phone conversation with Ulster Unionist leader David Trimble this evening.
Government sources said Mr Ahern tried to persuade the unionist leader, who has withdrawn his party from the review of the Good Friday Agreement currently underway, that there was no future in remaining outside this phase of the process.
Mr Trimble earlier called on the DUP to urge Tony Blair to act against Sinn Féin following the attempted abduction of Bobby Tohill in Belfast.
Mr Trimble, who yesterday pulled his party out of the review, was speaking following a one hour meeting with Mr Blair at Downing Street.
Speaking to journalists, the Ulster Unionist leader said there was now a duty on the Prime Minister to act.
He added that there was no point continuing with the review when the underlying problem of paramilitarism was not resolved.
Mr Trimble said: 'we hope he will act in a way that restores credibility to the process'.
The Ulster Unionists delegation suggested to Mr Blair that he bring the Independent Monitoring Commission into play immediately so that it could produce a report which could then justify or recommend further action by the government.
