An exit poll in the Republic of Ireland showed that Sinn Féin received 21.1% of the first preference vote and Fine Gael 21%, making the election outcome a close call.
Polls show Fianna Fáil has 19.5% of first preference votes.
It also showed that 20% of second preference votes went to Fine Gael and Fine Gael, compared with 17% for Sinn Féin.
Results are released at 22:00 local time and are conducted by Ipsos B&A for RTÉ, The Irish Times, TG4 and Trinity College Dublin. Its margin of error is 1.4%.
The results also show that the Green Party’s first priority support rate is 4%; Labor rate is 5%; Social Democrats are 5.8%; Solidarity before interests is 3.1%; Independents are 12.7%, Independent Ireland is 2.2%, and others is 1.9%.
The poll is based on 5,018 completed interviews, conducted immediately after people cast their vote at polling stations in 43 constituencies in the Republic of Ireland.
In the 2020 Irish general election, Sinn Féin received 24.53% of the first preference vote, Fine Gael received 22.18%, and Fine Gael received 20.86%.
The results of this poll set the stage for the official vote count, which will begin at 09:00 local time on Saturday and is expected to last throughout the weekend.
“Could be a challenge”
Analysis by Enda McClafferty, BBC News NI Political Editor
Exit polls are far from an exact science, but they can give a good indication of where votes are going.
In 2020, it correctly predicted a tight race between Fine Gael, Fine Gael and Sinn Féin, with only three seats separating the three parties.
If this exit poll is correct, Sinn Féin will be pleased with its performance.
Slightly higher than Fine Gael but lower than the nearly 25% support Sinn Féin achieved in 2020.
The party limped into the campaign on the back of a series of damaging controversies and a poor performance in June’s European and local parliamentary elections, when it received just 12% of the vote.
In a three-week campaign, it managed to regain lost ground and promised to bring about change.
But if the exit polls are correct, delivering on that promise could be a challenge.
The report suggests Fine Gael (21%) and Irish Defeat (19.5%) are likely to return to government seats with the help of two smaller parties and some independents.
While Sinn Féin’s path to power is more challenging as it once hoped to lead a coalition of left-leaning parties, it may struggle to gain support from the performance of these smaller parties.
But the true picture will only become clear once all the results are in.
Some of the 43 constituencies may not have final results until early next week.
The successful candidate is called a Dála Member of Parliament (TD) and there are 174 seats to be filled, but the Ceann Comhairle (Speaker) will automatically return.
More than 680 candidates are vying for the remaining 173 seats.
The number of seats required for a majority is 88, but no single party has been able to field enough candidates to win a majority alone.
The first session of the new Dáil (lower house of parliament) will be held on December 18, but coalition negotiations are unlikely to be completed by then.
The government will be formally formed when the House of Representatives votes to appoint a new prime minister.
Few expect a new government to be in place before 2025.