Sinn Féin has made huge gains over the SDLP in the Northern Ireland Assembly elections, while a strong DUP vote could give the Rev Ian Paisley's party more seats than the UUP.
The overall result due later today radically alters the political landscape of the North and threatens the future of the Belfast Agreement.
The DUP outpolled by around 20,000 votes the Ulster Unionists in terms of first preferences, sending a clear anti-agreement message to the British and Irish governments.
Another day of high electoral drama is in store today as the DUP, Sinn Féin and Mr David Trimble's Ulster Unionists Party battle to win the most Assembly seats. The result was unpredictable last night and will hinge on how preference votes are transferred in several of the constituencies.
If Sinn Féin emerges with the majority of seats, then the prospects of unionists agreeing to form an Executive with Mr Martin McGuinness as the likely First Minister appear very remote. While there has been speculation that DUP pragmatists might deal with Sinn Féin, the party leader Dr Ian Paisley emphasised yesterday that he would not negotiate with Sinn Féin.
"Anyone who talks to Sinn Féin will be out of my party," he said.
His remarks will make clear to the Taoiseach Mr Ahern and British Prime Minister Mr Tony Blair - who will be discussing the results when they meet in Cardiff today - how difficult it will be to restore devolution to Northern Ireland.
The first day of counting was disastrous for the SDLP, which with 118,000 votes slipped from first to last of the four main parties compared to five years ago. It was the first-preference poll-topper with 22 per cent of the vote in the 1998 Assembly election, but won only 17 per cent this time.
It won 24 seats five years ago but could drop to 20 or under in this election. Sinn Féin, which made gains at the expense of the SDLP, came second to the DUP with 24 per cent of the vote, up 6 per cent from 1998. Sinn Féin was on course last night to win around 24 or 25 seats, and possibly more if transfers go their way.
However, the Sinn Féin president, Mr Gerry Adams, who was seeking to win five seats in his West Belfast constituency, will have been disappointed to have seen his party pipped for that last seat by the DUP's Ms Diane Dodds, wife of Mr Nigel Dodds.
Mr Trimble remained bullish last night, hoping that the UUP could emerge with more seats than the DUP.
"My ultimate aim is to see a society here operating entirely peacefully and democratically and so, the first object now, as it was beforehand, is the matter of compelling republicans that they have to now abandon all elements of their military machine," he said.
Alliance, the Women's Coalition, and the Progressive Unionist Party fared poorly in the election.
The Women's Coalition could lose its two seats, while Mr Billy Hutchinson conceded defeat in North Belfast, although party leader Mr David Ervine managed to hold on to his East Belfast seat. Alliance leader Mr David Ford was also under pressure in South Antrim.
Independent candidate Dr Kieran Deeny caused a sensational upset by winning on a policy issue. He topped the poll in West Tyrone on a platform of maintaining acute services in Omagh hospital.
