Green Party TD Mr Eamon Ryan's bid for a presidential election nomination will be argued closely at the party's National Council meeting in Clonakilty today.
Though grassroots opinion gauged by The Irish Times is in his favour, there are leadership fears about the party's ability to finance and organise a five-week campaign.
These doubts became more evident following a meeting yesterday with the Labour leader, Mr Pat Rabbitte, and Labour's key adviser, Mr Fergus Finlay.
The Greens said in a statement that "confidential and sensitive discussions" were still underway with Labour and Independent TDs about the nominations.
The Green Party chairman, Mr John Gormley, said: "It is not a foregone conclusion that we will get the necessary 20 signatures from members of the Oireachtas.
"We have not received as many Independent nominations as expected, making us more dependent on Labour Party support. We are very grateful to the Labour Party for their promises of nominations and fully appreciate that it may prove difficult for some in Labour to be seen as major stakeholders in another party's campaign.
"Our candidate Eamon Ryan is very sensitive to these difficulties," he said, adding that he will proceed carefully.
Mr Ryan has so far won the support of Independent TD Mr Finian McGrath, Mr Tony Gregory and Trinity College senator Shane Ross.
However, the majority of Independent Oireachtas members have said they will refuse to sign his nomination papers.
The attitudes of Independent senator David Norris and Sen Fergal Quinn could also prove significant in coming events.
Galway East TD Mr Paddy McHugh is unlikely to sign Mr Ryan's nomination papers even though he said he had "the highest regard for him".
However, Oireachtas Independents should "not be a fall-back" for Mr Ryan, given that Fine Gael, Labour and the Greens insist they can form the next government, he argued.
"If it isn't possible for him to get 20 names from those parties then everything that they have been saying to us for the last year does not stand up," he said.
The Independent Donegal North-East TD, Mr Niall Blaney, said he had "no interest" in supporting Mr Ryan: "As far as I am concerned, it is a waste of money.
Wexford Independent TD Dr Liam Twomey said he would not be providing a signature either. He said he was backing the President, Mrs Mary McAleese, because she had nominated herself as an independent candidate.
"I don't think she's a Fianna Fáil candidate at this stage," Mr Twomey said. "I think Eamon Ryan has made his point. He has made a strong statement about the presidency and about the role of democracy."
The Cavan Monaghan Independent TD, Mr Paudge Connolly, said he was still undecided but he is considered unlikely to offer his signature to Mr Ryan.
"When he rang me I told him that I was undecided. I wouldn't give him a no and wouldn't give him a yes. I told him I would talk to him, I'd listen to what he had to say," Mr Connolly said.
Mr Jackie Healy-Rae, the Kerry South Independent TD, said he had decided against lending his support to Mr Ryan when he learned that he had smoked cannabis in the past.
"I have a terrible grudge against any people that have ever touched drugs. I don't know to what extent, but that's enough for me," he said.
The Independent TD for Wicklow, Ms Mildred Fox, has said she will not be a backer of Mr Ryan, while Mayo's Dr Jerry Cowley, Senator Mary Henry and Sligo Leitrim TD Ms Marian Harkin have all expressed support for Mrs McAleese.