Prime Minister Simon Harris called the election on the heels of a 10.5 billion euro ($A17 billion) budget that began to put money into voters' pockets during the campaign, largesse made possible by billions of euros of foreign multinational corporate tax revenues.
An opinion poll on Wednesday put Harris' Fine Gael on 20 per cent, level with Sinn Fein and just behind its main coalition partner Fianna Fail on 21 per cent. A broadly similar result in 2020 led the two centre-right parties to govern without left-wing rival Sinn Fein and they have redoubled a pledge to do so again this time.
The three largest parties were virtually neck-and-neck heading into the vote, with one party leader describing the race as "too close to call".
Polls will close at 9am on Saturday AEDT with a total of 174 seats in the country's parliament to be filled - more than ever before.
More than three million registered voters will pick their representatives across 43 constituencies, in a campaign that has focused on Ireland's housing crisis, the response to a dramatic increase in immigration, and economic management for the cost of living as well as potential future trade shocks.
After the 2020 general election delivered an inconclusive result, Fine Gael and Fianna Fail, two parties forged from opposing sides of Ireland's Civil War of the 1920s, agreed to set aside almost a century of animosity and share power.
Sinn Fein won the popular vote in 2020 but a failure to run enough candidates meant it did not secure sufficient seats in the Dail to give it a realistic chance of forming a government.
This time around, party leader Mary Lou McDonald fielded many more candidates in a vow not to repeat past mistakes, as she urged voters to elect a government of change without Fine Gael or Fianna Fail.
Polling day ends a lacklustre three-week campaign that seemed to fail to ignite a surge of enthusiasm among the public, after the election was officially called by Harris on November 7.
with PA
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