Inside Politics: The Taoiseach and the Tánaiste are this weekend facing stark political choices that will determine not only the future of the Government but the fate of their respective parties in the forthcoming general election, writes Stephen Collins.
Ahern's dilemma is whether he should lead on regardless of the damage to Fianna Fáil while McDowell has to decide whether there are any circumstances in which he can stay in Government without destroying the reputation of the Progressive Democrats.
The intervention yesterday of Manchester businessman John Kennedy, to vouch for the fact that money was paid to Ahern, may ease some of the pressure on the Taoiseach. But the fundamental propriety of a minister for finance taking a personal gift of stg£8,000 (€11,800) is the core issue that won't go away.
In some ways Ahern is facing the same kind of political choice that ended the extraordinary career of his old mentor and patron, Charles Haughey, in January 1992. If the Fianna Fáil-Progressive Democrats Coalition is to continue he will probably have to resign the office of Taoiseach. Unless he accepts that he should have acted differently in 1994 Mr McDowell will probably have to lead his party out of Government.
However, there is one very significant difference in the political equation now compared to the one that confronted Haughey. Back in 1992 Fianna Fáil simply did not have the numbers to survive in office without the support of the PDs; today there is a good chance that Fianna Fáil can soldier on to the end of the road next year, with Ahern continuing at the helm and as leader of a minority Government.
That is why many people in Fianna Fáil believe that Ahern will take a different road from the one followed by Haughey in 1992, and defy the PDs to do their worst.
The trenchant defence of the Taoiseach's position yesterday by the two most senior Fianna Fáil Ministers, Brian Cowen and Dermot Ahern, was a clear signal that the party is in no mood, at this stage at least, to change its leader at the behest of Michael McDowell. The forced removal of the late Brian Lenihan from the Cabinet during the 1990 presidential election campaign at the insistence of the PDs was cited by some Fianna Fáil TDs as a reason why they would never go down that road again. Mind you, there was no reference to the fact that it was the PDs who had forced the resignation of Haughey two years later.
Within the party it appears that Ahern will not be under any serious pressure to step down if the PDs pull out. Of course most almost all Fianna Fáil TDs are still hoping that the crisis can still be defused and that the Taoiseach will be able to come up with an explanation of the Manchester payment that will satisfy the PDs.
While nothing can ever be ruled out in politics it is very difficult to see how this can happen unless Michael McDowell backs down from his demand that the Taoiseach has to come up with a much fuller explanation for the Manchester payment than he has done to date.
The fundamental problem is that there is an obvious gulf between what Ahern believes is an acceptable standard of behaviour by a minister and what the PDs regard as acceptable.
Unless the Taoiseach can acknowledge that it was entirely inappropriate for him to have taken the money in the first place, the Tánaiste will have no choice but to leave Government, regardless of more detailed explanations.
Going on the Dáil arithmetic there is every chance that Fianna Fáil could continue in office at least until the Budget in December. The party has a nominal strength of 80 TDs, including Niall Blaney, who was elected as an Independent but who recently joined the party, and Michael Collins from Limerick East, who lost the whip because of the controversy over his offshore account, but who has continued to vote loyally with the party.
Beverley Flynn, who was elected as a Fianna Fáil TD in 1997, is now completely outside the fold, having been expelled from the organisation as well as the parliamentary party.
Still, she almost always votes with the party in the Dáil and would be inclined to keep Ahern in office, although she will have to extract something in return. Two of the Independent TDs, Jackie Healy Rae and Mildred Fox, supported Fianna Fáil from 1997 to 2002 and would probably do so again, at a price.
Assuming the Independents could be lined up, Ahern could continue in office as the leader of a Fianna Fáil minority government. That would enable Brian Cowen to introduce the expected €3 billion giveaway budget and go to the country early in the New Year.
The paradox is that both Fianna Fáil and Opposition TDs appear equally happy with this prospect. The Opposition believes that Fianna Fáil, which is already struggling in the opinion polls, would lurch into the next election with a badly-damaged leader.
"Bertie Ahern has been Fianna Fáil's greatest asset for more than a decade but he has used up all his accumulated political capital over the past two weeks and is now a liability. If he stays on Fianna Fáil are there for the taking," one Opposition strategist said.
Fianna Fáil people see it differently. The warm reception for Ahern at the ploughing championships yesterday and a stream of supportive e-mails and phone messages to the party over the past few days have convinced people around the Taoiseach that his personal popularity has remained intact and that the Opposition and the media are out of touch with the public mood.
A couple of professional opinion polls will indicate which assessment is closer to the mark but ultimately it is a matter of political judgment.
Ahern and his party will have to decide whether he has more to gain or lose by staying on. If their judgment since this crisis erupted over a week ago is anything to go on, they will make the wrong decision.
At almost every stage in the drama since The Irish Times disclosed that the Mahon tribunal was looking into payments made to Ahern when he was minister for finance in 1993 and 1994, the Taoiseach has made the wrong choice about what to say and how to say it.
The most disastrous errors were made during the interviews he gave on his constituency tours to Clare and Cavan. A unique feature of Bertie Ahern's occupancy of the Taoiseach's office has been his constant electioneering tours of the country. Week in, week out he spends a day trudging through at least one constituency. This has served to generate a huge level of continuing popularity for him which was the strongest weapon in the Fianna Fáil armoury.
The downside of this permanent election campaign emerged in the so-called "doorstep" interviews he gave over the past week or more. He said things he need not have said. He contradicted himself and tied himself in knots in Clare and Cavan. The Cavan interview, in particular, was so bad it prompted McDowell to raise the stakes much higher than before.
Even the decision of going on RTÉ television to give a long, deeply personal interview to Brian Dobson was highly questionable.
The tactic of appealing to the people over the heads of the Opposition and the media made sense at one level but there was always a danger that the technique, pioneered by Richard Nixon in his famous "Checkers" speech, would rebound, once the emotional temperature had dropped.
More seriously, in the interview designed to clear up the issues surrounding the way he had raised €50,000 from business friends in Dublin, Ahern also put on public record the fact of the Manchester payment of £8,000 sterling.
This was the time bomb that ultimately forced the political crisis which threatens to break the coalition.
It was in the Dáil that Ahern performed at his best. Enda Kenny, Pat Rabbitte and Joe Higgins did raise all the pertinent issues with him during leaders' questions last Tuesday but Ahern looked relatively comfortable dealing with them. It was the forum he knows best and a structure of debate that suits him.
He would have been far better advised to make the Dáil, where he is accountable to the people, the forum for his substantive response to the crisis rather than media interviews.
However, no forum can disguise the central problem facing Ahern.
It is that he will not accept that anything he did was wrong: taking substantial sums of money from business friends for his personal use, accepting the gift of a large sum from English businessmen, finding a mechanism to avoid paying tax on either sum, avoiding declaration under any set of ethical guidelines, then or now.
In the face of all these things the Taoiseach has stoutly maintained not only that he has broken no law but that he has done nothing at all wrong.
He has only accepted that he may have made an error of judgment by giving his opponents a stick with which to beat him.
Nothing else appears to give him any cause for regret.
So far the Fianna Fáil party has stood behind him, with just the odd waverer, and his colleagues accept that he has nothing to apologise for.
The logic of their position is that Ahern should therefore lead on, regardless of whether the PDs pull out. If public opinion turns against them, then it may be a different matter.
After the first flush of defiant emotion has passed, a more sober assessment of the political options will come into play. But the party has given Ahern such a blank cheque that it will be very hard to turn against him no matter how bad things get or what Ahern decides to do.
If he opts to tough it out and call the bluff of the PDs, most of his TDs will probably back him.
If the PDs pull out and he then tells them he is going to continue as leader, potential challengers will not have a leg to stand on if they continue to underwrite his actions as they have done to date.