Sinn Féin set for unprecedented gains in Irish election
Tallies suggest Sinn Féin is set to top constituency polls across the Republic, challenging the 90-year power duopoly of Fine Gael and Fianna Fáil.
The party appears to be faring better than an exit poll that reported a statistical three-way tie between the three main parties.
In a result symbolic of the surge, the first seat declared shortly after 4pmwas Sinn Féin's Donnchadh O Laoghaire, who topped the poll ahead of Fianna Fáil leader Micheal Martin.
Fine Gael Taoiseach Leo Varadkar was also outpolled by a Sinn Féin candidate in his Dublin west constituency, with Mr Varadkar only getting over the line after the fifth round of counting.
But the odds remain against Sinn Féin emerging with the most seats, primarily because it ran significantly fewer candidates than its two main rivals - 42 compared to Fianna Fáil's 84 and Fine Gael's 82
Fine Gael and Fianna Fáil have vowed never to go into government with Sinn Féin, and Fianna Fáil has ruled out a 'grand coalition' with Fine Gael.
If parties stick to their pledges then it would be extremely difficult for anyof the three to lead a majority government.
Smaller parties such as the Greens, Labour, the Social Democrats andSolidarity/People Before Profit - and a sizeable number of independent TDs - may all be courted as the main parties seek junior coalition partners.
Arriving at the RDS count centre in Dublin earlier, Mrs McDonald branded talk of excluding her party as 'undemocratic'.
She said she had been in touch with the Greens, Social Democrats and People Before Profit to discuss the prospect of them joining her party in government.
"It's been an election about change," she said.
"The extraordinary thing is that it seems that the political establishment -and by that I mean Fianna Fáil and Fine Gael - are in a state of denial. Theyare still not listening to what the people have said.
"I want us to have a government for the people. I want us to have ideally agovernment with no Fianna Fáil or Fine Gael in it.
"I have started the contact with other parties to explore over the next days whether that is a possibility."
Our Political Editor Ken Reid was in Dublin.