By Padraic Halpin and William James
Ireland's main opposing parties will have to start thinking about forming an unprecedented alliance, analysts say, after exit polls suggested voters had rejected the ruling coalition, many opting instead for protest groups and independents.
Enda Kenny's government looks to be the latest victim of European voters' growing antipathy to mainstream politics.
Although under his premiership Ireland has bounced back from a bailout to become the continent's fastest-growing economy, voters said the fruits of the recovery had not been shared.
"There's total disillusionment with party politics. The independents and the smaller parties seem to be almost like the last hope for the country," said John McKeever, a voter in Dublin.
Exit polls suggested the only viable option may be a problematic alliance of old rivals Fianna Fail and Kenny's Fine Gael - although even their combined support was set to fall below 50 percent of the vote for the first time.
If neither side is able to form a government, however, fresh elections would have to be called.
The centre-right Fine Gael captured 25 to 26 percent of the vote, the exit polls said on Saturday.
That is far below the 36 per cent it won five years ago and the 30 percent opinion poll rating it enjoyed at the start of campaigning.
Current coalition partner Labour was in line to win just 7 to 8 percent of the ballot, which spending minister Brendan Howlin said meant they were out of the equation for the next government.
Fianna Fail was set to rise to 23 percent.
One Fine Gael junior minister, Michael Ring, said he would "of course" be open to a prospective deal with Fianna Fail after another exit poll late on Friday showed a similar result.
He was the first senior member of either party to say so after weeks of rejecting the notion.
Fianna Fail leader Micheal Martin hinted that he would first try to form a government with other groups, however.