2 November 2007. Perhaps it will ultimately prove to be merely yet another example of how Bertie Ahern always triumphs in the end, regardless of the level of adversity. Or perhaps, just perhaps, the date will be seen as the beginning of the end of the quite brilliant career of the man who unquestionably has been the best political strategist the country has produced since de Valera.

The figures in the Irish Times/TNS MRBI poll couldn't have been any starker. The poll rating of 33% for Fianna Fail was worrying for the government, but not crisis territory. After all, the party had been there before . . . lower even . . . during the last Dail and ultimately emerged triumphant.

But there is no gloss that can be put on the other two figures that featured in the main image on page one of the Irish Times. Bertie Ahern 43%, down 15. Brian Cowen 49%.

Choppy waters without buoyant Bertie There was a time, not that long ago, when it would have been unthinkable for Ahern to be outshone by any politician in the popularity stakes, never mind somebody from his own party.

For the past decade, Ahern has been like a buoyancy aid, keeping Fianna Fail afloat in often perilously choppy waters.

Government TDs have gratefully clung to him and opposition leaders in quiet moments have privately expressed their frustration and exasperation at the electorate's seemingly unbreakable love affair with the Taoiseach. But no more.

The drop of 15 percentage points . . . not even stones drop at that rate . . . was bad enough. But to have Cowen, the man Ahern suprisingly chose to designate as his heir apparent, so publicly ahead of him in the ratings was particularly damaging.

The three leaders of Fianna Fail prior to Ahern . . . Jack Lynch, Charlie Haughey and Albert Reynolds . . . were all the victims of plots hatched against them. But in the 13 years since he became leader of Fianna Fail, Ahern has been untouchable. His enormous popularity with the electorate meant there was never any doubt that he was the best man to lead Fianna Fail. Three successive election victories was evidence of that.

But strip away that popularity . . . as the Irish Times poll so publicly did . . . and Ahern is like Samson without his hair:

extremely vulnerable. It would be an exaggeration to say that the plotting has begun against Ahern. For starters, none of the main contenders to succeed him are interested in moving against him and TDs are by no means panicking over the poll results. But the murmuring has definitely started.

"There are rumblings about Bertie, " one TD admitted this weekend. "Tolerance levels have dropped, " said another senior figure, adding: "15 points is very serious." Another TD said: "This is the first time ever that the idea is being challenged that he's so popular that he's untouchable." Even those who insist that Friday's poll in no way brings forward the date of his departure accept that "the time is coming."

There is barely-concealed anger among Fianna Fail backbenchers at some of the mistakes that Ahern and his ministers have made in recent weeks. If Noel Dempsey is something of a bete noire for the position he took on the provisional licences . . . "I got more calls on the provisional driving licences than any other subject in a year, " fumed one backbencher . . . the Taoiseach is by no means insulated from the criticism.

"Arrogant" and "too smart" are two of the terms used to describe Ahern's public response to criticism about the hefty increases in ministerial pay.

There is a view that Ahern wouldn't have made the same mistakes two or three years ago. "He wouldn't be doing these things if he was going to be there long term, " one TD told the Sunday Tribune. You don't need to have Bertie Ahern's unrivalled nose for survival to realise how dangerous it will be for the Taoiseach if this sentiment becomes more widely held. There are two words that put the fear of God into any prime minister interested in staying in office: 'lame' and 'duck'.

"I think his number is up, " said one Fianna Fail source bluntly when asked about the poll result. When it is put to him that if and when Ahern goes, it will most likely be at a time of his own choosing, the source demurs: "If we fall further in the polls, fellas will get anxious and you will see stalking horses emerge.

There's nothing to focus minds like opinon polls."

Taoiseach's last Christmas Views are certainly mixed when Fianna Fail politicians are canvassed for their opinion on Ahern's future. Some don't rule out him leading the party into the next general election. But there is a not insignificant number who believe this is the beginning of the end and that the upcoming Christmas could well be Ahern's last in the job of Taoiseach.

"The Christmas period could be interesting if things don't improve from this poll. You asked me about Bertie's future . . . it's the polls that will provide the answer. It will depend on the polls between now and Easter, " said one TD, who added that, if pushed on the question, he believed Ahern will be gone as leader before the summer. This was echoed by another TD who said that the Taoiseach would be "ok" for "as long as he's a vote getter" but that he believed Ahern would go in the next year or so, adding: "His day is done."

Fianna Fail TDs swear that the issue of the Taoiseach's finances is not coming up with constituents, but others in the parliamentary party argue that doesn't mean that Ahern's credibility hasn't been seriously eroded by his spell in the witness box in Dublin Castle. And there is concern that those in the party who are forced to defend him will also suffer from the fall-out. "The longer he remains, the more it will rub off on those closest to him, " one senior source said, adding that could prove to be a particular problem for the anointed one, Brian Cowen.

Most TDs take a cynical view of Ahern's decision to lay his hands upon the Tanaiste. The most common belief is that by grasping Cowen to his bosom, the Taoiseach is keeping him in a tight clench and restricting his room for movement. The worry for those who support Cowen is that because of this assocation, he could be dragged down if Ahern's drop in popularity continues.

The burden of the chosen successor While it is accepted that Cowen will never make any move against Ahern, some of his admirers in Fianna Fail are unquestionably getting itchy feet and his positive poll rating compared to Ahern will only add to that, party sources say.

They are worried that while Cowen is currently the clear front runner, he could yet be passed out by a candidate not hamstrung by the burden and limitations of being the chosen successor in a struggling government. "Cowen needs to handle this very carefully, " said one very close observer. "It's making it very dificult for Cowen, the longer Bertie stays on, " said another TD.

One issue that could bring matters to a head very quickly is the job of President of the Council of the European Union.

The belief is that suggestions the job has been earmarked for Tony Blair are wide of the mark . . . the former British prime minister is not remotely interested . . . and that Ahern, after all his legwork on the EU Constitution, would have a pretty good chance of landing the position if he wants it.

It would arguably be the ideal exit for Ahern, moving to a job that is, if anything, more prestigious than the office that he currently holds and, crucially, at a time of his own choosing.

But not everyone believes the changeover will be so seamless. "I don't believe it will be of his own timing. Fifteen points is very serious, " said one senior party source. "He could be pushed, " said a TD, matter-of-factly.

Others, however, are more wary of such predictions, believing Ahern's unparalleled politicial instincts will allow him to survive, possibly even beyond the local elections. "He's the smartest political operator of them all. He won't be forced out and nobody will make a move. He will pick his own timing, " said one very close observer.

But the problem for Ahern is that this is by no means the unanimously held view it was just a few short weeks ago. In politics, a leader is only as good as his or her last opinion poll rating and 2 November, 2007 could yet come to be seen as a watershed.