Outgoing Taoiseach Bertie Ahern is aiming for a third term in office while the Opposition's Alliance for Change hopes to end a decade of Fianna Fail rule.

Experts believe the turnout could be the lowest ever due to a declining trend and the numbers of college students sitting exams.

The outgoing Coalition of Fianna Fail and the Progressive Democrats parties look unlikely on the evidence of opinion polls to have enough TDs to form a Government.

Fianna Fail may have to make a deal with Labour, or with the Greens for the first time in its history.

However Fine Gael leader Enda Kenny could also lead an alternative government with Labour and the Greens if they can muster a majority of TDs in the 166-seat Dail parliament.

If Mr Ahern is re-elected as Taoiseach he will become the second-longest serving EU premier currently in office.

The last time a Fine Gael/Labour alliance put Fianna Fail out of power was in 1982.

A total electorate of 3,066,517 is entitled to vote today for the 466 candidates running in 43 constituencies.

Fianna Fail is fielding 106 candidates, followed by Fine Gael with 91, Labour with 50 and the Progressive Democrats with 30. The Greens and Sinn Fein are also represented by candidates in most or all of the constituencies.