Nationalists protested throughout Ireland today - the day elections to the Northern Assembly were due to take place.
Sinn Féin chairman Mr Mitchell McLaughlin warned the situation that brought about the postponement of the ballot is not likely to be resolved soon.
The British government postponed polling last month, saying that without a clear declaration by the IRA its operations had come to a permanent end, elections would be pointless because the unionists would not share power with Sinn Féin.
Sinn Féin has organised demonstrations in 30 towns and cities in the North and the Republic and began leafleting commuters in Dublin this morning.
The SDLP will hold a mock ballot in Belfast later today.
The Taoiseach, Mr Ahern, also reiterated his opposition to the decision describing it as a "wrong judgement". He said the democratic process envisioned in the Belfast Agreement was the only way to proceed, adding that further efforts to bring about elections must be made.
But McLaughlin was pessimistic: "It is difficult to envisage how political circumstances in the autumn or June next year will be any different from the circumstances in which elections should have taken place today or even next month".
Sinn Féin-organised pickets were staged in Dublin along major thoroughfares and in Navan, Drogheda, Dundalk, Longford, Mullingar, Kinnegad, New Ross, Kilkenny City, Naas, Carlow, Enniscorthy, Wicklow and Bray.
Protests are also planned for Cork City, Clonakilty, Mallow, Waterford, Tralee, Tuam, Ballinasloe, Westport, Ballina, Charlestown, Castlebar and Sligo.
Sinn Féin's protests were condemned by senior Ulster Unionist Sir Reg Empey. "Instead of bringing people out on to the streets in towns and cities, Sinn Féin should redouble their efforts by helping to resolve the current political logjam," he said.
"Street stunts are no substitute for real product".
Speaking today outside Castle Buildings in Belfast, Sinn Féin president Mr Gerry Adams said: "The Irish Government opposed the cancellation of the elections. Indeed, every political party in Ireland opposed it. Only UUP leader David Trimble and the British government supported this undemocratic action.
"The cancellation of elections is a subversion of democracy . . . and creates a dangerous political vacuum.
"No party should have a veto over fundamental rights, equality or parity of esteem. It is critical that politics is allowed to work," he said.