Protests are set to greet the arrival of British Prime Minister Tony Blair in Dublin next week for talks over the deferrment of the Northern Ireland elections.
Speaking at a rally in the capital, Sinn Féin members confirmed they would be staging the action to voice their "anger and frustration".
Sinn Féin TD for Dublin West, Mr Sean Crowe, said: "We are here to express our anger and frustration at the fact the elections have been deferred.
"This is first of a number of rallies to be held across the country. Another protest will take place when Tony Blair arrives on Tuesday."
The rally was held in response to Mr Blair's announcement on Thursday that the elections would not be held on May 29th as planned.
He decided to visit Dublin after the Taoiseach, Mr Bertie Ahern said he disagreed with the decision.
Mr Crowe and Independent TF Mr Finian McGrath addressed today's lunchtime rally outside the GPO in Dublin.
Statements of support were read out on behalf of Labour's Mr Joe Costello and trade unionist Mr Mick O'Reilly.