The Sinn FΘin president, Mr Gerry Adams's, charge that the US Congressional Colombian hearings would prejudice the upcoming trial there of three Irishmen has been rejected by the Government.
Speaking following Mr Adams's long-awaited rejection of the summons, a senior Government source said the US authorities would regard Mr Adams' refusal to appear before the House of Representatives very seriously.
Fresh documentation alleging links between the IRA and the FARC guerillas in Colombia will be submitted today to the House of Representatives' International Affairs Committee.
"The fact that Irish-American figures have not been coming out today in defence of Sinn FΘin indicates that they believe, or fear that there will be stuff in it that will be embarrassing," one source told The Irish Times.
Former Fine Gael Taoiseach Mr John Bruton said the refusal of Mr Adams to travel to Washington did not serve the interests of the three jailed men, Mr Martin McCauley, Mr James Monaghan and Mr Niall Connolly.
"By going to Washington and explaining the position it would have created the best possible atmosphere for the trial, whereas the refusal creates the worst atmosphere," he told The Irish Times.
"The argument that he would prejudice the trial is entirely bogus. If things are as reasonable as he says they are then what is the problem? Mr Adams's claim that the hearings will damage the peace process is equally bogus. What damage will it do? Who will do the damage?" he said.
Sinn FΘin's original denial of knowledge about the three men has come back to haunt them, he said.
"Any other party would have been excoriated if it had been caught out in this way," said Mr Bruton.
"For the last century and a half Irish nationalists have looked for help to Washington. This week Washington looked for help to an Irish political leader in its enquiry into the sources of terrorism. Mr Adams turned them down flat.
"How will anybody ever take him seriously in Washington again? What will American's make of Sinn FΘin's continuing links with the IRA now?" said Mr Bruton, who has been frequently critical of Sinn FΘin in recent times.
Former Progressive Democrat leader Mr Des O'Malley was equally critical of the decision, which followed SF's refusal this month to appear before a meeting of the Oireachtas Foreign Affairs Committee on the same issue.