Elected Socialist Party MEP Joe Higgins expects United Left Alliance candidates to gain four seats, with the possibility of a fifth, allowing it to form a "relentless, unremitting opposition" in the next Dáil.
Mr Higgins, who was elected on the third count in Dublin West, expects his Socialist Party colleague Clare Daly to be elected in Dublin North, with possible gains for the ULA in Dublin South Central and Tipperary South. Richard Boyd Barrett is fighting for the last seat in Dún Laoghaire.
Speaking at the Dublin West count centre in Coolmine, Mr Higgins said he was pleased with "the new advances made today for the socialist alternative".
He described it as a new development in Irish politics and said the Socialist Party would be discussions with fellow ULA candidates about forming a new movement.
"Obviously there will be many discussions but we in the Socialist Party would be of a mind that there is a huge vacuum on the left. There is a need for a new movement to represent the working class in its widest sense - the public sector, the private sector, pensioners and young people.
"We will now set our minds to that with our colleagues in the United Left Alliance and others about launching a new movement," he said. "We will be putting up the real opposition and the real alternative, not just inside the Dáil, but outside as well. I anticipate movements of people power, movements of workers, movements in communities in opposition to new attacks that will come - perhaps water charges, perhaps a home tax - that these new parties are committed to, which are all simply more burdens on working class people."
Mr Higgins was the third candidate to be elected in Dublin West, following Labour's Joan Burton, who was elected on the first count, and Fine Gael's Leo Varadkar who was elected on the second count. Fianna Fáil's Brian Lenihan is poised to take the fourth and final seat.
Mr Higgins said it would be "a monstrous betrayal" were ULA candidates to offer support to the Fine Gael government. "No way would we contemplate any such thing."
