The Green Party is expected to enjoy a surge following the European elections.
Counting started on Saturday morning but results will not start to emerge until Sunday evening due to the Europe-wide embargo.
However, an exit poll has suggested the Green Party will top the poll in Dublin.
The increased support looks widespread, even accounting for a 4% margin of error, and could see an unexpected boost in Ireland’s two other constituencies, RTE said.
The Green Wave rolls on in IrelandMay 25, 2019
Party leader Eamon Ryan gave the outlook a cautious welcome.
“We cannot yet count our chickens but the exit polls for the Irish Greens are extremely encouraging,” he said.
“Our MEP candidates Ciaran Cuffe, Saoirse McHugh and Grace O’Sullivan have put their heart and soul into campaigning across the three constituencies over the past few months.”
He told RTÉ earlier: “We knew there was going to be a Green vote and it’s everywhere; it’s rural Ireland, urban Ireland, younger Ireland, older Ireland.
“It’s reflective of a green wave of thinking that’s happening all over the world, all across Europe. We were waiting for it to rise here and it has risen today.
“We still don’t know the results obviously. We’re going to be close on a couple of the European seats. I think we’re in with a chance.”
The Irish broadcaster commissioned a RedC exit poll. The polling firm spoke to 3,230 voters in stations across Ireland.
Ireland has 13 European Parliament seats.
A Europe-wide embargo means the first results in that poll cannot be declared until 10pm on Sunday.
Local council elections results are also being counted, as is a referendum on divorce laws – with a Yes vote set to reduce the lengthy period separated couples have to wait before they can obtain a formal divorce.
- Press Association