Taoiseach Enda Kenny has opened the door to Fine Gael doing business with Sinn Féin, in a move that will cause major disquiet within his party.
In a dramatic shift from his pre-election position that Gerry Adams's party is "not fit for government", Mr Kenny repeatedly refused to rule out a future coalition.
It follows a softening of Sinn Féin's stance that it would only enter into a coalition if it was the senior partner.
The party's deputy leader Mary Lou McDonald now says she wants to be in government and a "conversation" needs to be had between now and the next election.
Mr Kenny, who has been leader of Fine Gael for 15 years, has always maintained that there was no way his party would work with Sinn Féin. However, asked whether this might change in light of Ms McDonald's comments, he replied: "I said I wouldn't do business with Fianna Fáil so, depending on the result you gave as a member of the electorate, politicians have to work with the result.
"So Sinn Féin seem to be converted now to a position of changing their stance."
However, Social Protection Minister Leo Varadkar said yesterday that a Fine Gael deal with Sinn Féin "wouldn't be possible".
"I can't see it. I wouldn't seek a mandate for it and I think our policies are so far apart that it wouldn't be possible.
"It's actually the public and the people who will decide the make-up of the next government. But I absolutely do not envisage and would not seek a mandate for coalition with Sinn Féin," he said.
A number of senior Fine Gael sources were last night shocked by Mr Kenny's inconsistency, with one saying: "This is ridiculous stuff. I can't understand why he would open up this can of worms."
Sources said the vast majority of the party were still opposed to working in a coalition with a party that had strong links to the IRA.
Mr Kenny was given several opportunities by reporters to reject the idea of a coalition with Sinn Féin, but only went so far as to say they have "a long journey to go".
"I saw the comment from the deputy leader of the Sinn Féin party. I'm glad that they are now beginning to realise that in order to get things done you need to be there. I'm not going to make any further comment on that," he said.
When pressed, Mr Kenny said the issue didn't arise in the current administration as they have an arrangement with Fianna Fáil. But rather than rule out the possibility after the next election, the Mayo TD said he expected Fine Gael to have "a much stronger result" next time.
Earlier this month, Government chief whip Regina Doherty faced a major backlash after stating she was open to a coalition with Sinn Féin.
The Meath East TD, who has been one of Gerry Adams's fiercest critics, said there were some "fabulous" people in the party.
"There are some incredible people in Sinn Féin; incredibly smart, articulate, thoughtful and could I work with them? Of course I could, yeah," Ms Doherty said.
Former Fine Gael director of elections Frank Flannery was the last senior party figure to give legitimacy to the idea in 2009 - but was demoted soon after.