To borrow a phrase from P.J. Mara, history is nibbling at Bertie's bum. He gave an assured and confident account of himself in the Dail yesterday, but I could not shake the feeling there was a spectre at his shoulder.

The spectre, had he been present in the flesh, would have treated the issues being raised with contempt. Rather than listing the plethora of dates and meetings as Bertie did, the spectre would have referred disdainfully to "no such meetings", and denied any knowledge of the people involved.

But the spectre did not attend in person. Instead, the litany of events described by Bertie recalled a different time. Politics was done differently then, and he knows it. Ministers could, and did, decide which developers would get designation. There were Ministers to be in with, and Ministers who didn't really matter much. And there was one through whom all decisions were funnelled eventually - the one at the top.

Long ago, Bertie Ahern must have decided the one thing he would never be able to live down was his relationship with the man whose spectre still hovers at his shoulder. He is haunted by the fact that the culture introduced by Charles J. Haughey to his own party was an insidious poison, with a half-life that has lived on long after his departure from the scene.

Even in the diluted form that a chemical half-life produces, that poison has debilitated the entire political system. That catch-cry that politicians hear most often nowadays - "ye're all the bloody same" - really means that politics didn't decommission the Haughey reprocessing plant until it was too late. And the waste and effluent built up over the years that plant was in full operation continue to contaminate to this day.

And the only ones who could have decommissioned Haugheyism were his own people. Others tried, but Haughey was always supported by enough tough people to ensure he survived. Among them was the man who now finds himself desperately trying to recall events of 10 years ago.

Des O'Malley, I presume, must have sat through yesterday's debate with something akin to bewilderment (if he still has the capacity for such a naive emotion). Twelve years ago, or so, he was expelled from Fianna Fail for "conduct unbecoming a member of the party". His crime was to abstain from a vote in the Dail Eireann on an issue of principle.

Yesterday, he heard the leader of his former party describe how they had written to Padraig Flynn, in pursuit of £50,000 that had allegedly gone missing, and had not even had the courtesy of a reply four months later.

No disciplinary action is apparently contemplated against this member. And yet, what conduct could be more unbecoming to any party member than to decline to answer fundamentally important questions about allegedly missing money?

More than Fianna Fail have an interest in the Gilmartin contribution. Ireland - and the whole of Europe, indeed - is entitled to a straight answer from our Commissioner. Did he get £50,000 from Tom Gilmartin? For what? What did he do with it? Where is it now?

These are simple questions. The answers might suggest fraud, even theft - or they might not. There could be some straightforward explanation. Whatever it is, we're all equally entitled to it. Padraig Flynn once, at the height of his powers, said to me about Dick Spring "he might not be of my party, but he's Tanaiste of my country". That night (the night of the eight billion), he still saw himself as a loyal member of a political party.

And if his own party - the people who had a primary interest in the money - could not get a written acknowledgement of their questions, let alone a straight answer, we are all entitled to ask: why did they let the matter rest there? Is it possible they didn't really want to know? Is it possible they knew all along that this was just one more example of the way things used to be done, and it was better not to inquire too deeply into it?

To put it another way. It's impossible to draw a line in shifting sand. That is what Bertie Ahern is trying to do. He is trying to clean up that act for the future without confronting the past. And the past keeps rearing its head. Haugheyism hasn't gone away, you know.

Whatever happens now, this week has been a turning point. The business of Government, of managing events and dealing with politics, will be much more difficult now. This Government, to some considerable extent, has had a charmed life. That's over now. So is the media honeymoon the Government has enjoyed - the longest I remember.

Some commentators will no doubt be writing today that the Opposition "didn't lay a glove" on Bertie yesterday. They're missing the point. Nobody was able to produce a smoking gun in Dail Eireann yesterday, but the Opposition found a role.

They saw enough cracks in the Teflon to be able to keep Fianna Fail deputies in their seats until the debate was over. And they know that people everywhere are entertaining a doubt now about the stability and cohesion of the Government that wasn't there a fortnight ago. There's a credibility gap - and gaps like that have a way of growing until they become intolerable. The Government hasn't been broken - but it has almost certainly peaked.

Over Christmas, I wrote in this newspaper about the two tribunals that "No one can now predict with certainty that they won't reach into the heart of Government. Although the Flood tribunal is beset with difficulties, its chairman and sole member is demonstrating all the air of a man determined to get to the bottom of things. The lower-profile tribunal, chaired by Judge Moriarty, is ticking away nicely (or dangerously, depending on your perspective)."

The Moriarty tribunal starts ticking a bit more loudly today, with the commencement of public hearings. The excitement may be only starting.