The counting process has begun in Ireland’s General Election with an exit poll indicating the result is on a knife edge.

The poll reported an extraordinary statistical dead heat between Fine Gael, Sinn Fein and Fianna Fail, all on around 22%.

If the results are borne out when the ballots are counted, the task of forming a coalition government looks extremely complicated.

Tallies should give an indication of the outcome as the day progresses, with the first results expected on Sunday afternoon. Counting is expected to last at least two days.

The uncertainty created by the poll has even thrown up the spectre of another General Election.

Ballot boxes opened at count centres around the country at 9am with a lengthy count process ahead.

Fine Gael and Fianna Fail have vowed never to go into government with Sinn Fein, and Fianna Fail has ruled out a “grand coalition” with Fine Gael.

If parties stick to their pledges then it would be extremely difficult for any of the three to lead a majority government.

READ MORE: Irish political leaders cast their ballots for General Election 2020

Smaller parties such as the Greens, Labour, the Social Democrats and Solidarity/People Before Profit – and a sizeable number of independent TDs – may all be courted as the main parties seek junior coalition partners.

The exit poll indicated a remarkable three-way tie, with Fine Gael on 22.4%, Sinn Fein on 22.3% and Fianna Fail on 22.2%. The poll has a 1.3% margin of error.

While the poll suggests a major breakthrough for Sinn Fein in the Irish Republic, the party is still unlikely to emerge with the largest number of seats because it ran significantly fewer candidates – 42 compared to Fianna Fail’s 84 and Fine Gael’s 82.

There are 160 seats in the Dail parliament. The speaker is automatically re-elected, leaving 159 seats up for grabs and 80 the magic number for a majority.

Vote transfers will be crucial in the proportional representation contest

Taoiseach Leo Varadkar’s last government – a minority Fine Gael-led administration that included several independent TDs – was sustained in power through a historic confidence and supply arrangement with Fianna Fail.

That landmark pact between two parties founded from opposing sides of Ireland’s civil war of the 1920s took 70 days to negotiate following the inconclusive 2016 General Election.

A new confidence and supply deal cannot be ruled out – potentially a reverse of the last one, with Fine Gael supporting a Fianna Fail led-minority.

General Election Ireland 2020A first preference vote for Sinn Fein Leader Mary Lou McDonlad seen on a ballot paper (Niall Carson/PA)

The fractured vote could yet force Ireland’s two traditional political superpowers to contemplate the once unthinkable – a grand coalition in government together.

Brexit did not feature prominently in an election campaign which was instead dominated by domestic issues like spiralling rental prices, record-breaking homeless numbers, controversy over the state pension age and a struggling health service.

The exit poll, carried out by Ipsos MRBI on behalf of The Irish Times, RTE, TG4 and UCD, suggested that only 1% of voters highlighted Brexit as their main concern.

Health (32%) and housing or homelessness (26%) were the most important deciding factors in how people voted.

Fine Gael business minister Heather Humphreys has said it was not a mistake for her party to put Brexit at the centre of its re-election strategy.

“A lot of people obviously thought Brexit is over… Brexit is far from over,” she told RTE Radio One.

“Brexit is still a big threat but some people live in the moment and a lot of people thought Brexit has gone away – it has not gone away.”

Fianna Fail candidate Jack Chambers has said it was clear “there is a strong desire for change” and that people want “an alternative to Fine Gael”.

General Election Ireland 2020The counting process is set to last two days (Niall Carson/PA)

He again ruled out a coalition with Sinn Fein. “Our word is our bond,” he told RTE.

Sinn Fein’s director of elections Pearse Doherty has said his party will sit down with all parties and independents to discuss forming a government.

“The view from Sinn Fein is clearly that the best outcome of this election is a government without Fianna Fail or Fine Gael and the worst outcome would be where we have been, Fine Gael and Fianna Fail,” he said.

Mr Varadkar will find out if he has retained his seat in Dublin West at Phibblestown Community Centre in the city.

Sinn Fein president Mary Lou McDonald is likely to top the poll in Dublin Central when votes are counted at the RDS in the city.

Fianna Fail leader Micheal Martin will be at Nemo Rangers GAA club in his native Cork city for the outcome of the race in his Cork South Central constituency.

Counting is taking place across the state’s 39 constituencies.

There is a mix of three, four and five-seat constituencies.