Ireland is facing an historic shift in its political landscape as the outgoing government looks set to suffer humiliating losses in the general election.
Hours after ballot boxes opened, early tallies appear to back two separate exit polls showing the incumbent Fine Gael/Labour coalition have no chance of being returned to power on their own.
Junior partner Labour fears an electoral bloodbath as Tanaiste, or deputy prime minister, and party leader Joan Burton gears up for a dogfight to retain her own seat.
Several Government ministers including Labour's Alex White, Kathleen Lynch, Ged Nash and Kevin Humphreys are not looking forward to a nail-biting weekend, with counting expected to take days under Ireland's complex voting system.
Fine Gael ministers Pascal Donohoe and James Reilly are also uncomfortable.
In a remarkable comeback after its near wipeout at the last election, the senior Opposition party Fianna Fail could almost double its seats.
But the once dominant party in Irish politics will remain a long way from its heyday majority, which tumbled with the economic crash it presided over nearly a decade ago.
Sinn Fein looks set to continue its march south of the border with an expected increase in its representation in the Dublin parliament, the Dail, by around 50%.
Mounting disillusionment with mainstream parties has also opened an unprecedented fracture in the Irish electorate, with smaller parties and Independents set to reap the rewards.
Uncertainty looms over whether a government can be formed at all once the two million-odd ballots are counted.
Power could be handed to civil servants for at least weeks as negotiations to form a stable pact are hammered out and a second election remains a possibility.
Mark Mortell, Taoiseach Enda Kenny's closest adviser, said Ireland would have to review its "political system" once the outcome of its most uncertain election in recent times is decided.
"The only word I can use right now is deep disappointment," he said.
The top-ranking aide admitted the chance of another general election was "now very, very high".
The first government TD (MP) to concede his seat, Labour's Eric Byrne, declared he was relieved.
"It is going to be pure hell to be re-elected into a chaotic parliament," he added.
One of the few possibilities for stable government, it appears, would be sworn enemies Fine Gael and Fianna Fail setting aside their more than 80-year-old feud dating back to Ireland's civil war.
The pair, both centre-right, have swapped power since the foundation of the state.
Such a "grand coalition" would also break new ground in potentially handing the Dail a definitive left-right split for the first time in history.
Asked about the prospect, Mr Mortell said: "We're each going to have to consider the situation and we're going to have to talk to the Labour Party too."
He added: "What you've got here is an extraordinary situation. It is a massive fracturing of the political system.
"It creates immediately a huge amount of volatility and if you look just across into Europe, and what's happened in Spain and Portugal, this does mean we're going to have a very, very interesting couple of weeks ahead of us and very, very demanding ones."
Fianna Fail frontbencher Michael McGrath said there is an onus on everyone elected to reflect on their own and their party's position "to bring about a stable government".
There is also the prospect of a minority government taking power but seasoned commentators have warned about the instability of such a loose pact.
According to surveys of people leaving polling stations by pollsters Ipsos MRBI for the Irish Times and by Behaviour and Attitudes for state broadcaster RTE, Sinn Fein, Independents, smaller parties and newcomers are all likely to make significant gains.
The first exit poll showed Fine Gael on 26.1% of first preference votes; Labour on 7.8%; Fianna Fail on 22.9%; Sinn Fein on 14.9%; Anti Austerity Alliance/People Before Profit on 3.6%; Greens on 3.5%; Social Democrats on 2.8%; Renua on 2.6%; and others on 16.1%.
RTE's showed Fine Gael on 24.8% of first preference votes; Labour on 7.1%; Fianna Fail on 21.1%; Sinn Fein on 16%; Anti Austerity Alliance/People Before Profit on 4.7%; Greens on 3.6%; Social Democrats on 3.7%; Renua on 2.4%; Independents on 11%; and the formal Independent Alliance on 3%.
However, the figures come with a health warning, given Ireland's unusual single transferable vote system.
More than 550 candidates fought in 40 constituencies to become one of just 158 TDs - eight seats fewer than the 2011 election when Fine Gael and Labour took office promising a democratic revolution.
Once a clear picture emerges from the weekend counting of votes, the parties will have until March 10 - when the Dail is scheduled to resume - to forge a power-sharing deal.