Fianna Fail, Fine Gael and the Labour Party last night united in a call on Sinn Fein to explain its links with the three men suspected of offering explosives training to drug-financed Colombian terrorists.
The combined assault by the biggest three political parties in the Republic is the first sign that the recent political honeymoon enjoyed in the Republic by Sinn Fein is coming to an end.
Earlier the SDLP leader, Mr John Hume, said it was essential that Sinn Fein immediately clarify its links with the three men detained in Bogota, and, in turn, their links with the FARC guerrillas.
In Washington, the United States warned the IRA it could face US penalties should it be determined that the group had connections with Colombia's largest left-wing guerrilla army.
A State Department spokesman, Mr Philip Reeker, said Washington would look harshly on any link between the IRA and the FARC following the weekend arrests. He said US officials understood that at least two of the three men arrested had IRA connections.
"We would be concerned if it were established that the Irish Republican Army were assisting, sharing information or in any way collaborating with a violent terrorist organisation such as the FARC," he told reporters.
The former minister for foreign affairs, Mr David Andrews, said Sinn Fein must clarify its association with the arrested men in Bogota.
"How can Sinn Fein reconcile its repeated publicly stated anti-drugs position with the fact that suspected leading IRA members, with long-standing associations with the party, are seemingly involved with the organisation known for drug-smuggling, kidnapping and racketeering?" he asked.
Earlier the Taoiseach, Mr Ahern, avoided an opportunity to criticise Sinn Fein when he bade farewell to Mr Hume after nearly an hour of talks.
So far, Mr Ahern believes he has to refrain from direct criticism of Sinn Fein. But Mr Andrews's comments were cleared with the Taoiseach's office, The Irish Times understands.
So far, Sinn Fein has attempted to deny connections with the three men arrested.
In Co Donegal the Fine Gael leader, Mr Michael Noonan, urged Mr Ahern to take a stronger line against Sinn Fein.
He said the Taoiseach should state publicly if he "is still confident about the bona fides of the republican movement in light of the security briefing the Minister for Justice has received from the Garda Siochana on the activities of the three".
The deputy leader of the Labour Party, Mr Brendan Howlin, said "the tolerance and the silence" shown by the Republic's political parties towards Sinn Fein had obviously been abused.
For years Sinn Fein had escaped deserved criticism because of the need to keep them "onside" with the political process. "But this softly-softly approach is at an end," he told The Irish Times.
The three men arrested in Bogota have told investigators they were just tourists in the country and had committed no crimes, local media reported yesterday.
They also told prosecutors they were in the demilitarised zone, under rebel control, to determine the status of peace negotiations between the government and the FARC guerrillas, according to reports.
Additional reporting Reuters, AFP