Sinn Fein's national chairman, Mr Mitchell McLaughlin, admitted yesterday that dissident republican groups had "probably managed to attract additional people" during the break in the peace process.
However, he believed it was "not a burgeoning situation".
Mr McLoughlin, who was speaking in Dublin after an ardchomhairle meeting of the party, commented on yesterday's bombing of the Dublin-Belfast railway line in south Armagh, by describing those responsible as "the enemies of the peace process."
He said: "Omagh reminds us what they're capable of doing, whether they did it deliberately or not. These people are operating on the logic that they only have to be lucky once, in their terms - which would be desperately unlucky for the rest of us."
He said, however, "the process has shown itself to be extremely resilient. Unionists and republicans and nationalists coming from totally different directions were coming to understand that. "For those on the dissident side, unionist or republican, it is a problematic situation when they see that politics is starting to get down and deliver."
He said the dissidents should "get behind the efforts to achieve a negotiated and just settlement and I think that would represent the position that is popularly supported throughout the island".
Mr McLaughlin also commented on the Dail motion of no confidence in the Government, saying it had been elected to do a job "and we wish they would just get on with it".
Asked whether he felt a general election should be called, he said: "Sinn Fein's position is that if there is an election, and when there is an election, we're ready. And we believe the political conditions exist where parties like us will do very well because clearly there is considerable dismay at the disclosures, and clearly people are looking for an alternative to all of that and we believe we can offer it."
