Taoiseach Bertie Ahern has secured the support of Independent deputy Jackie Healy-Rae for a full five-year term in government, the Kerry South TD told The Irish Timeslast night.
However, he refused to disclose the terms of their arrangement, describing it as "a private, personal document".
Negotiations were also believed to be well-advanced with other Independents and the Progressive Democrats. Finian McGrath was understood to be seeking firmer commitments on detail while Michael Lowry was said to be "assessing the situation". A Fianna Fáil spokeswoman refused to comment on the negotiations other than to say there were "ongoing contacts".
Mr Healy-Rae revealed he had met Mr Ahern in the Taoiseach's office at the conclusion of their negotiations. "I finished up in his office this afternoon and I'm very glad to say that I signed up a deal with him for the next five years."
Expressing firm confidence that the arrangement would last the full five years, he said: "I have the deal signed up with the Taoiseach this evening, who I highly respect because Bertie Ahern is an exceptional man in my view. He honours his word to the very last detail and I want to say that also about his top officials: they are very upright, very good and very honourable and if they will make a deal with you, you won't have to go back fighting or grousing or groaning or moaning.
"I've signed up a deal this evening for five years and I'm absolutely delighted that the people that will benefit here at the end of the day are the people of south and southwest Kerry."
However, Mr Healy-Rae refused to disclose the contents of the document he had agreed with the Taoiseach. "There is no hope in the world that I'd even dream of mentioning it to you. This is a private, personal document for the people of south and southwest Kerry that sent me up here on a mission and, by God I feel that I have very honourably responded to their calls this afternoon. I'm so delighted to go home to Killarney tonight and to say that I have this thing sorted out."
However, he did acknowledge that improvements in his constituency were a principal element of the deal. "There are things of national importance as well, but I'm not going to name them here."
Forecasting that Mr Ahern would be elected Taoiseach when the Dáil resumes this week, Mr Healy-Rae said: "It is a master-stroke and he must be an extremely happy man when this will happen on Thursday afternoon."
Asked if he had reservations about the possible inclusion of the Green Party on the same team, he said he was sure Fianna Fáil would not allow the Greens "to dictate or formulate policy" on such issues as once-off housing or the export of live cattle. "I have great confidence that when they do a deal, whether it is with the Greens or the Blues or the Reds, that they'll do a mighty deal and I have great faith in them."