THE Fianna Fáil-Green coalition will fall; the only question now is when. That is the only logical conclusion to be drawn from Friday's Irish Times poll showing that Fine Gael now has an extraordinary 17-point lead over Fianna Fáil.

There is so much bad news in the poll for Taoiseach Brian Cowen that it's hard to know where to start. But aside from the massive gap between the two main parties, the dissatisfaction with government (an unprecedented 86%) is close to the top of the list, followed closely by Cowen's miserable satisfaction rating of 18%.

Successive polls have shown that Fianna Fáil has lost half its support since the general election. And having allowed Fine Gael to break through the glass ceiling of 30% support that had been in place since 1985, the main opposition party is now close to the 40% zenith it enjoyed under Garret FitzGerald in the general election of November 1982.

The figures for the Greens should be equally alarming for Fianna Fáil strategists. The Green core vote has now dropped to 2%. That is PDs territory and everybody knows what happened to the PDs. The Green support base is seriously unhappy as evidenced by the 93% dissatisfaction rating among party voters.

The Green leadership has serious decisions to make. Their courage in eschewing the populist approach is admirable but it isn't washing with voters. And by staying in an unpopular government, the party risks annihilation. The temptation to find an issue to cut and run – in the process hopefully garnering public support – will be irresistible in the coming weeks and months.

It will also be a temptation for Fianna Fáil backbenchers. Though most view the prospect of a general election with horror, there may be a few who foresee electoral salvation in taking a stand against an unpopular government decision. And there will be plenty of those in the coming months.

The same holds for the likes of Michael Lowry and Jackie Healy Rae. They are wily political operators and they will know instinctively when the benefit of supporting the coalition is outweighed by the downside of associating with such an unpopular government. Cowen's options seem to be narrowing by the week.

"Frankly, I think he's finished," was the verdict of one Fianna Fáil TD this weekend. "There looks to be no way back," was the comment of another government TD. And tough as that may be on the taoiseach who has been so unfortunate in taking office when he did, it's hard to disagree.

His body language at Thursday's launch of Fianna Fáil's European election campaign was not good. He appeared subdued and there was none of the energy that was so evident when he took the last general election campaign by the scruff of the neck. "He's gone into himself," said one decidedly glum government figure.

There are many in Fianna Fáil who still admire Cowen and are loyal to him. "He's worth 10 Bertie Aherns," said one. But they acknowledge that this view is not shared by the electorate and that the taoiseach is, politically, a 'dead man walking'.

Even if nobody emerges to challenge his leadership, it is hard to see how the government, given its current dissatisfaction rating, can implement the next round of spending cuts and tax increases later in the year. Can a government with a satisfaction rating of 10% introduce a property tax or tax child benefit or cut social welfare? Much more immediately, will it be able to get the National Asset Management Agency (Nama) legislation through the Dáil before the summer? Nama may be the right option to tackle the banking crisis, but it's virtually impossible to explain to voters that exposing the state to €90bn of debts is a good idea. National Treasury Management Agency boss Michael Somers' comments on Nama to a Dáil committee on Thursday didn't provide much reassurance. "It's going to be shaky, very shaky," one government source admitted this weekend.

It's simply impossible to see anything other than a Fine Gael-Labour government after the next general election. Eamon Gilmore obviously thinks so. On Friday, he abandoned his 'not ruling anything out or in' approach to coalition and rejected the possibility of government with Fianna Fáil. Gilmore realises the government is in such bad odour with the voters than any hint that Labour might consider coalescing with Fianna Fáil could be hugely damaging.

The real battle at the moment is between Fine Gael and Labour for the divvy-up of cabinet seats, a factor in the increasingly tetchy exchanges between the two parties last week. If Friday's poll result was replicated in a general election, Fine Gael would be calling the shots. The party leadership is determined that, if and when its time comes, there will be no repeat of the paralysis that characterised the 1982-1987 Fine Gael-Labour coalition, when the government appeared incapable of taking the tough decisions to tackle the recession.

Privately, Fine Gael people are not impressed with what they see as Labour's populist approach to the economic crisis. And if George's Lee's strong comments to Labour's Alex White on Nightly News with Vincent Browne on Wednesday are anything to go by, Fine Gael may become a lot more vocal about that. Not that any of that will deter the parties in agreeing a programme for government once the numbers add up.

Fine Gael must be thanking the stars that it didn't get the extra three or four seats that would have won it the election two years ago. But for that late surge to Fianna Fáil, Enda Kenny would have been taoiseach facing into the economic tsunami. Cowen would be leader of the opposition, glorying in the Rainbow government's discomfort and waiting for a general election that could bring an overall majority. "We would have been shagged," admits one Fine Gael figure.

Instead Fianna Fáil could be down to 40 seats and Fine Gael is facing into the upcoming elections with more optimism than in any previous contest for over a quarter of a century. After over 70 years on the hind tit of Irish politics, Fine Gael's time, it seems, has finally come.