Fianna Fail leader Micheal Martin has said a second general election in 2020 cannot be ruled out if the Green Party votes down the programme for government deal.
Fine Gael, Fianna Fail and the Green Party have been balloting their respective members to back the document, which took some five weeks to put together.
The outcome of the membership votes among the three parties will be announced on Friday.
The Green Party has the highest threshold of the three parties to secure the approval of its membership.
Two thirds of members registered to vote on the proposals must back the deal.
Mr Martin says if the programme for government deal is voted down, a second election is possible and his party would talk to Independent TDs about forming a government.
“If the Green Party don’t back the programme for government then then we will not have secured the necessary backing and clearly won’t have the support of a majority in the Dail.
“We are in a political crisis and I don’t think there is a solution to it in the short term.
“There is no magic plan B.”
Asked what will happen if the deal is voted down, he told Today FM: “There could be a general election, that’s fair.
“Secondly, we have had good discussions with Independent TDs and we have had good discussions with them.
“There are 18 or 19 centre ground independents out there.”
Mr Martin ruled out Sinn Fein as a potential coalition partner if the Green Party don’t back the programme for government deal.
“The Social Democrats and the Labour Party wrote back to us so I wouldn’t rule them out as a possibility.”
Fianna FÃ¡il will Reignite, Restart and Renew the Economy. Our number one priority will be to repair and rebuild the Irish economy, support businesses in these tough times, and help people get back to work. #PfG pic.twitter.com/J4GlAMevcS— Fianna FÃ¡il (@fiannafailparty) June 20, 2020
Taoiseach Leo Varadkar also warned there is no Plan B if the document is rejected this week.
“I know there are some people in my party who are counselling me and advising me to have a Plan B on the shelf, but I decided not to do that because we entered these coalition talks in good faith with Fianna Fail and the Greens,” he told Newstalk FM.
“If it is defeated, we will have to sit down over the weekend and see what the options are.”
Mr Varadkar said Fine Gael wanted to go into opposition and let Sinn Fein form a government, but it did not work out.
He said: “Sinn Fein, despite their protestations, never really tried.
“They didn’t even come up with a framework document with the far-left.
“They voted for Mary Lou initially, but they couldn’t even agree a common policy among themselves.
“Given the opposition on the left were so incapable of delivering on any of the promises they made, we felt that we should step back in and this was our best attempt and perhaps only attempt to form a government.”
Meanwhile, Sinn Fein president Mary Lou McDonald said that if the agreement fails to garner enough support, Sinn Fein will speak to other parties.
What's on the table at this point in time, a combination of Fianna Fail and Fine Gael, the political establishment cemented together, is certainly not changeSinn Fein president Mary Lou McDonald
While her party won the popular vote in February’s election, Sinn Fein failed to establish a left-wing coalition because they did not secure enough numbers to reach the 80 seats required for a Dail majority.
“We will talk to the Social Democrats, we will talk to Green Party, People Before Profit and to independent formations, to establish in the first instance, can we agree on a very strong programme for government and can we agree that we have a sufficiency to form the core or the spine of a government for change going forward,” she said.
“If that being the case, then it will be necessary, from a numbers point of view, to talk to the other parties as well, and that’s consistent with what I’ve been saying all along, which is I will talk to everybody.”
Ms McDonald told RTE that the country is facing “more of the same” of Fianna Fail and Fine Gael, “this time officially in bed together”.
“I have views around the track record of others, and the policy positions of other parties, but nonetheless, once the people have their say and the votes are cast, well then it’s incumbent on every party to talk to each other and to establish the best basis for a government going forward,” she added.
“The best basis for the new government, on the back of the last election, is a government that is truly new and transformative and a government of change, and what’s on the table at this point in time, a combination of Fianna Fail and Fine Gael, the political establishment cemented together, is certainly not change.”