BRIAN Cowen's resignation has added to the doubts as to whether the general election will still happen on 11 March or instead at an earlier date in February.

In theory, with Cowen staying on as a caretaker taoiseach and the Green Party committed to ensuring the finance bill goes through, the government should be able to survive the confidence motion put down by Labour and the threatened confidence motion from Fine Gael, which would be specifically focused on Brian Cowen as taoiseach.

But in the current atmosphere, all theories can probably go out the window. Everything hinges on the Greens and, to a lesser extent, on independents Michael Lowry and Jackie Healy-Rae.

Green Party TDs and senators were yesterday discussing the Taoiseach's announcement. In a brief statement they said they would meet again this morning to consider the situation. Given the deterioration in relations between the coalition partners, it cannot be taken as guaranteed that the Greens will endorse the government or Cowen in any confidence motions.

To those within the political bubble that is Dáil Eireann, the idea of two different people holding the jobs of taoiseach and Fianna Fáil leader may be logical enough. However, the general public will find it harder to get their heads around it. The inevitable line from the opposition – that if Brian Cowen isn't good enough to be leader of Fianna Fail, how is he good enough to be taoiseach – will find a resonance with many voters. And, with a general election pending, that will increase the pressure on the Greens not to vote confidence in either Cowen or the government, and bring about an immediate dissolution of the Dáil.

Inevitably, the pros and cons of such a move will have been thrashed out by Green deputies and senators yesterday and today. There may be a view that the Greens might get some bounce from being seen to call time on the government. But with a general election due on 11 March anyway, it is doubtful whether the Greens will receive much credit from such a move after three and a half years in coalition with Fianna Fáil.

It would also run directly contrary to the line to which they have been steadfastly sticking since 22 November – that getting through the finance bill is of paramount importance and the Greens would stay in government long enough to see that through.

In the current hothouse atmosphere, there is no guarantee that line will continue to prevail. Whatever about voting confidence in the government in response to the Labour motion, the Greens will be extremely squeamish about voting confidence in Brian Cowen as taoiseach in response to Fine Gael's motion.

They will be acutely aware that the argument that it is in the national interest to do so – to ensure the finance bill is passed – won't cut much ice with an electorate who certainly don't want Cowen continuing as taoiseach, and for whom the technicalities of the finance bill are not of paramount importance.

Against that, if the Greens bring down the government prematurely, they will sabotage the finance bill and risk being accused of being flaky and of doing a U-turn.

Until we know what the Greens decide, there are several scenarios. Possibly the most likely scenario, though far from certain, is that Cowen continues as caretaker taoiseach, Fianna Fáil elects a new leader and the Greens grit their teeth and vote confidence in both Cowen and the government, on the grounds that it is necessary for the good of the country to pass the finance bill. The election would therefore go ahead on 11 March.

An alternative scenario is that the Greens, under intense pressure from the media, the electorate and their own grass roots, decide that they cannot vote confidence in either the government or Brian Cowen. If that happens, the government will fall immediately and Brian Cowen will have to go to Aras an Uachtaráin to seek an immediate dissolution of the Dail, with a general election taking place in the middle of February.

It would then fall to the next government to pass the finance bill – something they may not wish to do for political reasons and which could cause economic problems in terms of investor confidence in Ireland.

There is a third potential scenario: the Greens could withdraw from government – resigning their ministries – but vote with Fianna Fáil on this week's confidence motions on the grounds that there is simply no alternative to getting the finance bill through. Such a move would allow them stick to their word about being committed to the finance bill while putting some distance between the party and Fianna Fáil.

None of the solutions will look particularly attractive to the Green Party. All of them leave the party open to a certain amount of criticism. But it may all come down to this blunt summation of the Green's dilemma from a close observer yesterday: "They either want to get the finance bill through or they don't."