Sinn Féin will not be helping either Fianna Fáil or Fine Gael to form a coalition government, party leader Gerry Adams has said.

With final numbers in a heavily fractured Dáil not expected until Monday, Gerry Adams dismissed any idea that his party would support one of the traditionally dominant forces in Irish politics – Fine Gael and Fianna Fáil.

“We aren’t going to go in there (to government) and betray our electorate and betray the other people who need a progressive government,” he said.

“We are not going to go in and prop up a regressive and negative old conservative government, whatever the particular party political complexion.”

Adams' rejection of what would be a left-right coalition maintains the position his party adopted during the lacklustre election campaign.

With support for establishment parties plunging to a near record low, prospects for a new coalition government are in deep disarray and weeks of protracted negotiations are on the cards.

Taoiseach Enda Kenny ruled out resigning or re-running the poll.

Fine Gael suffered a hammer blow, losing about 30 seats, while the Labour Party was humiliated by the prospect of retaining fewer than 10 seats.

The other stories of the vote are the revival of Fianna Fáil, which led the country at the time of the economic collapse five years ago, and Sinn Féin, which has continued its steady growth.

The fracturing of traditional centre-right politics suggested widespread disaffection with the once dominant forces and austerity – a mirror of the voter schism which has crippled parliaments in Spain, Portugal and Greece.

Predictions point to a remarkable electoral swing where the political powerhouses of Fianna Fáil and Fine Gael will struggle to secure 50% of popular support for the first time in history.

The clearest majority would come from Fine Gael and Fianna Fáil setting aside their historical rivalries, borne out of the civil war and cemented over the last 90-odd years.

In a remarkable comeback after its near wipe-out at the last election, Fianna Fáil could almost double its seats.

Mounting disillusionment with mainstream parties opened an unprecedented opportunity for smaller parties and independents.

Sinn Féin will be the third largest party.

Fine Gael and Fianna Fail, both centre-right, have swapped power since the foundation of the state.

Such a “grand coalition” would break new ground in potentially handing the Dáil a definitive left-right split for the first time in history.

More than 550 candidates fought in 40 constituencies to become one of 158 TDs – eight seats fewer than the 2011 election when Fine Gael and Labour took office promising a democratic revolution.

Parties will have until March 10 – when the Dáil is scheduled to resume – to forge a power-sharing deal.