Sinn Féin will again attempt to form a government if Fine Gael, Fianna Fáil and the Greens this week fail to do so.
The memberships of all three parties are currently voting on whether to accept to the programme for government negotiated in recent months.
The Green Party has the hardest task in front of it, with party rules requiring a two-thirds majority in order to enter government.
On The Hard Shoulder this evening, Sinn Féin leader Mary Lou McDonald said she will return to the negotiating table if the programme is rejected.
"What needs to happen on Saturday, if that is the case, is that we need to move to plan B,” she said.
“And in all fairness Plan B really ought to have been Plan A, because Fianna Fáil and Fine Gael and back in business together again is not the change people voted for and the fact is Sinn Féin was excluded.”
"Parties of change"
She said Sinn Féin would reach out to the “other parties of change” to try and form the “core or the spine of a new government for change” without Fine Gael or Fianna Fáil standing in the way.
She admitted that the “numbers are tricky” for any government that does not include the two parties and insisted she has no fear of another election if that is what is needed.
“We are in the grip of a public health emergency,” she said. “I think that has to shape your view or your attitude towards an election in the very near future – but I certainly would not regard another election as a catastrophe or a crisis.
“In a democracy, you can never regard an election as a crisis. I mean it is part of the process but let’s not pretend anything other than that would be very, very difficult given the current restrictions that are in place.
“But if it is an election, Sinn Fein will go, and we will contest the election and we will again set out our programme.
“We will run more candidates and we will go, and we will again say to people who know that Fine Gael and Fianna Fáil are not the change they voted for, they know that together those parties can’t be trusted, and we will go and we will ask them to give us a mandate.”
Deputy McDonald also rejected the Green Party leader’s claim that the programme for government is a “left-wing document.”
On Newstalk Breakfast this morning, Deputy Ryan said the new government would be entering power at “one of the most challenging times possible” but insisted planned increases in borrowing would allow for immediate investment in housing, health and transport.
Deputy McDonald said the policies on housing and health are intolerable and 'wishy-washy.'
“If this is the approach that is adopted, we are looking at years more of housing crises and people unable to purchase their own home, indeed unable to even afford their rent,” she said.
“That is an intolerable proposition. It is certainly not a left-wing and it is not a sensible proposition.
“Equally, on the area of public health it is no more than wishy-washy in terms of Sláintecare.”
You can listen back to the full interview here.