The Green Party is set to top the European poll in Dublin, an exit poll suggested.
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 Irish broadcaster commissioned a RedC exit poll.
The polling firm spoke to 3,230 voters in stations across Ireland.
The main trend from the Dublin constituency is the projected poll-topping performance of the Green Party’s former junior minister Ciaran Cuffe on a suggested 23% first preference vote.
The RTE TG4 poll suggests that a candidate from Ireland’s largest party, Fine Gael’s Sean Kelly, could be re-elected, with the survey of voters in the South constituency putting him on 16% support.
Fine Gael’s Mairead McGuinness looks likely to top the poll in the Midlands/North West constituency, the research suggests.