Thirteen candidates in the running for Lenihan's seat
A total of 13 candidates are lining up to replace former Finance Minister Brian Lenihan in the Dublin West by-election.
But the result is regarded as wide open with no clear favourite emerging from the pack.
All of the political parties are running candidates, with Independents also in the field.
Despite its continued unpopularity in the polls, especially in Dublin, Fianna Fail strongly believes it is in with a chance of winning.
The party is running Councillor David McGuinness in the hope of retaining the only Dublin seat the party won in the 2011 General Election.
But there will be stiff competition from the rest of the party machines.
Fine Gael's candidate is Cllr Eithne Loftus, Labour has Cllr Patrick Nulty and the United Left Alliance-Socialist Party runner is Cllr Ruth Coppinger.
Sinn Fein is running former councillor Paul Donnelly and the Green Party has a previous candidate in the constituency, Roderic O'Gorman.
Fis Nua's candidate is Peadar O Ceallaigh and the Independents are Barry 'Caesar' Hunt, Benny Cooney, John Frank Kidd, Jim Tallon, Gary Birmingham and Brendan Doris.
Mr Hunt is a former contestant on TV's 'The Apprentice' programme.