The Sinn Féin ardchomhairle member, Mr Alex Maskey, has urged republicans not to lose sight of the gains they have made through their involvement in the peace process.
Mr Maskey, a former lord mayor of Belfast, described the process as "our agenda", and said republicans must not now lose ownership of it.
Stating that Sinn Féin was concerned that the political vacuum would degenerate further during the summer, Mr Maskey repeated the party's demand for the Northern Ireland Assembly elections to be called immediately.
He said republicans anticipated obstacles in the process and that "it would be us who would have the most work to do in keeping it going".
The fight for rights had a heavy price, "not only in terms of the political work we must be prepared to do but also in the initiatives and risks we need to take to ensure that this process does not stagnate or unravel into failure," Mr Maskey said.
He was speaking at the annual Wolfe Tone commemoration in Bodenstown, Co Kildare, which was attended by the Sinn Féin president, Mr Gerry Adams, and other senior republicans.
Gardaí maintained a discreet presence at the commemoration,which they said was attended by about 1,400 people.
There were eight bands and a colour party from the Roddy McCorley Society in Belfast, a group of former prisoners.
Mr Maskey said the survival last week of Mr David Trimble as leader of the Ulster Unionists would only be victory if it moved the peace process forward. While political engagement was a two-way process, he said, republicans should intensify their efforts to reach out to unionists. "Now is the time to move up a gear."
Saying that the British government should not allow unionism to dictate the pace of change, he said the Government in Dublin "must stand up and be counted".
"Among the issues the Irish Government must confront is the need for the truth about the involvement of the British state in the murder of its citizens," he said.
Mr Maskey used the commemoration to call for support for Sinn Féin's campaign in local elections in the Republic next summer. He said he believed the party's success in the general election last year would be repeated.
The party opposed the draft EU constitution proposed by the Convention on the Future of Europe and said too much sovereignty had already been ceded to the EU. "That draft, if adopted, would be a giant step in the ongoing project to transform the EU from a partnership of states into a single state," Mr maskey said.
"The demand for a single EU state, which would be another world power, does not come from the peoples of Europe."