Talks between Fianna Fáil and the Green Party to agree a programme for a coalition government have broken down without a deal, throwing new uncertainties on which parties will be in a position to form a government when the Dáil sits next Thursday.
Confirming that the talks had collapsed at a press conference in Dublin shortly before 6pm, Green Party leader Trevor Sargent said: "We have taken this as far as we possibly can and the ball is now in the court of others."
"We are not giving up hope but at this point we have taken it as far as we can. Our door is open to all who wish to discuss the formation of a sustainable and stable government. We're not closing the door on any particular prospects."
Mr Sargent, who did not take part in the talks, told RTÉ news afterwards that the talks had been "cordial, very businesslike and professional" but that the objectives of the Green Party were not sufficiently reflected in the programme for government that was on the table. He cited issues such as proper planning, housing, reform of local government, the health service and education as among those upon which agreement was not reached.
The party said in a statement that the differing approaches between the parties on these issues were "insurmountable".
Around 800 members of the Green Party were to attend a meeting in Dublin on Sunday, which the party said has now been cancelled.
Mr Sargent said the talks had to conclude on the basis that it would not be possible to put together a package of measures that could be put to members by that time "in all good faith".
However, Fianna Fáil's Seamus Brennan insisted this evening that progress could still be made and he said he believed the leaders of both parties - Bertie Ahern and Trevor Sargent - are available to discuss the problem areas that were not resolved during the talks.
Mr Brennan said he believe there had been "enormous progress" on some issues during the talks but that in the end, there were a number of areas that clearly could not be agreed upon to the satisfaction of the Green Party.
"We identified an enormous range of common areas - so we achieved a lot," he said.
Mr Brennan said Fianna Fáil remained available to try to deal with those issues that were of concern to the Green Party.
However, he also said that Taoiseach Bertie Ahern had "a number of options" open to him.
"And I know that as Taoiseach he will be reflecting on those options."
Mr Sargent did not this evening rule out entering talks with Fine Gael leader Enda Kenny, who has still refused to rule out the possibility of heading a government.
Party chairman John Gormley, who was a member of the delegation at Government Buildings, described the breakdown of talks with Fianna Fáil as "a no-fault divorce".
He added that the collapse had been "amicable" and he wished Fianna Fáil well.
The parties had been in intensive talks throughout the day, beyond the Wednesday deadline for a deal initially imposed by the Green Party, in an attempt to put together a joint programme for government. The Green Party was obliged to put any deal to its members at the now abandoned special convention in Dublin.
The Green Party did not outline the areas where the two sides had reached agreement, but said the issues where they had not found common ground included climate change, including "forward-thinking transport and congestion solutions", funding to bring the education system into the 21st century, the transformation of local government, and reform of the healthcare system.
Green negotiator Dan Boyle said that some of the tougher issues, which were flagged at the start, could not be bridged by the end of the talks, but there was "movement every day on every issue".
Fianna Fáil has previously resisted the Greens' demands that the new government should order a 3 per cent cut in Ireland's annual carbon dioxide emissions to cope with global warming. Fianna Fáil also resisted pressure to abandon its plan to cut the top rate of income tax by 1 per cent to 40 per cent, though the Greens are supportive of cutting the standard rate by 2 per cent to 18 per cent.
Last night, some Fianna Fáil sources indicated that the M3 motorway, planned for near the Hill of Tara, and the US military's future use of Shannon were also obstacles.
The confirmation that the talks have fallen apart now means Taoiseach Bertie Ahern's options are now more limited in terms of putting together a stable government headed by Fianna Fáil.
Fine Gael leader Enda Kenny has still failed to rule out the possibility of heading a government with Labour and he has also held talks with acting Progressive Democrat leader Mary Harney.
Fianna Fáil was believed to be seeking to form a coalition with a comfortable majority made up of the Green Party and former partners the Progressive Democrats before inviting a number of independents to support its government.