Two of the three seats have been declared a three-way battle

Two out of three seats in Ireland's parliament have been filled, and Fianna Fáil is leading a strong fight in the country's general election.

With all 43 constituencies counted for the first time, the first half of the three main parties' popular percentages were: Fianna Fáil 21.9%, Fine Gael 20.8%, Sinn Féin 19.0%.

So far, 126 of the 174 seats have been filled, as counting began on Sunday morning.

Fianna Fáil, which has been in a coalition government with Fine Gael and the Green Party, is expected to win more seats.

Counting resumed on Sunday morning in an election with 59.7% of the vote – the lowest in more than a century.

The leaders of Ireland's three main political parties were re-elected on Saturday to serve in the Dáil (the lower house of the Irish parliament).

Micheál Martin of Fianna Fáil, Simon Harris of Fine Gael, and Sinn Féin leader Mary Lou McDonald have overcome their initial obstacles by keeping their seats.

Now, they all face an even bigger challenge – trying to form the next government.

Labor Party leader Ivana Bacik was also re-elected in the Dublin Bay South constituency.

Social Democrats leader Holly Cairns and Independent Ireland leader Michael Collins retained their seats in Cork South West, and

Aontú leader Peadar Tóibín was re-elected in West Meath and Richard Boyd Barrett from People Before Profit-Solidarity was returned to Dún Laoghaire.

Roderic O'Gorman of the Green Party was the last major party leader to be re-elected, in Dublin West.

He is the only one of the Greens' 12 sitting TDs to retain their seat, with former Green party deputy leader and government minister Catherine Martin having previously lost the Dublin Rathdown race.

O'Gorman said Green candidates received “very few referrals” from either Fianna Fáil or Fine Gael, the party's former allies.

“I don't think they did anything for us, but I didn't expect them to do us any good,” he said.

Fianna Fáil and Fine Gael worked together in the outgoing government, and after the first day of counting, they appear poised to return to government.

If they agree to do so, they may need the support of one of the smaller parties or a number of independent TDs expected to be elected as the counting of votes continues on Sunday.

Sinn Féin says it also wants to be in the next government, and the party is ready to talk to other parties and independents.

But, based on current forecasts, the scale of the challenge facing Sinn Féin is enormous.

Political pundits are currently predicting that Fianna Fáil and Fine Gael could get more than 80 seats combined – within touching distance of the golden ratio of 88 TDs needed for a majority in the Dáil.

The same experts believe that Sinn Féin can secure around 40 seats.

But even if it achieves that, it will still fall far short of what is needed for a Dáil majority.

If so, Sinn Féin will have to look to smaller and independent parties.

However, smaller teams are expected to have one count when all their TDs are confirmed.

If Sinn Féin turns to independents, it will get a very different set of TDs.

Finding common cause in such a situation will be another major challenge for the team.

To complicate matters, Fianna Fáil and Fine Gael have insisted they are not interested in sharing power with Sinn Féin due to fundamental policy differences on a number of issues.

There is widespread belief that talks to form a new government could go beyond Christmas and into the New Year.

After being one of the most talked about issues of this election, independent candidate Gerry Hutch has officially lost the Dublin Central constituency.

At one point he had a lead of 2,000 votes over Labour's Marie Sherlock, but was overtaken after a series of reshuffles between Green Party and Fianna Fáil candidates.

Hutch's win would be more remarkable – the year before he had won acquitted of aggravated murder when a man was shot at a boxing weigh-in event. The judge described him as someone who had been involved in serious crime in the past.

Analysis – BBC News NI political editor Enda McClafferty

Gerry Hutch may feel robbed after being asked to defend a seat in Dublin Central.

But he did not seem sad about his defeat when he arrived at the counting center at RDS.

Surrounded by reporters, the thug walked through the hall to congratulate Labour's Marie Sherlock who put him in the last seat.

He is known as a man of few words, but when asked by BBC NI if he plans to run again, he said he will.

“I've been running all my life so yes I would go again,” he said

He also said he was not surprised by the more than 3,000 first-choice votes he received.

“I expected more to be honest,” he said

He was challenged about his past crimes but refused to answer any questions.

After shaking Sherlock's hand, he left the facility surrounded by reporters and ended up running out of the building to avoid the attention of the media.

So what's wrong with the man who was poised to be the subject of the Irish general election?

A key moment came when Social Democratic candidate Gary Gannon was elected much earlier than expected.

The transfer of funds to the outcast People Before Profit candidate propelled him to the quota.

That started a series of transfers from Green and Fianna Fáil candidates that allowed Labour's Marie Sherlock to close the gap with Hutch.

The surplus from Paschal Donohoe was finally enough to get past his Hutch for the last seat.

But as one statistician pointed out it could have easily changed for Hutch and while there was a small path to Sherlock's victory no one expected him to find it.