It may have been Spy Wednesday when Frank Dunlop broke, but for the Flood tribunal this week was Christmas come early. Yet Dunlop's volte- face did not just drop into the tribunal's lap.

Wednesday's dramatic revelations of payments to councillors were the culmination of months of legal sleuthing that saw Dunlop irretrievably painted into a corner. Faced with having to explain the inexplicable, he chose to come clean.

This week could mark the turning-point in a long and dirty battle of attrition between those who believe there was widespread corruption in Dublin planning in the 1970s and 1980s and those who want to conceal this for as long as possible.

It will be some time before Mr Justice Flood delivers his final report, but it is clear to anyone who witnesses the daily proceedings in Dublin Castle that the tribunal has found good reason to believe many of the allegations it is investigating.

There is a secret history to this tribunal, though, one that is not reflected in the daily accounts of what happened on the floor of the Printworks Hall in Dublin Castle.

For over two years Mr Justice Flood and his legal team have contended with forces seen and unseen, a concoction of would-be witnesses and their legal, financial and media advisers, who have fought tooth-and-nail to prevent or delay the evidence coming out.

Money is no object for many of the wealthy individuals who are the subject of these allegations. Rafts of expensive lawyers and other advisers have been drafted in to serve their interests. High Court actions are launched with little concern for the enormous costs involved. Top-dollar public relations consultants are hired, seemingly to sit on their hands all day.

Beyond the arena of the tribunal, Leinster House takes a keen and sometimes active interest. Politicians kick to touch when asked about the allegations they face, saying the tribunal will deal with them "in the fullness of time". Others pooh-pooh the latest findings from Dublin Castle in off-the-record briefings to political correspondents. Backbenchers are encouraged to scoff at the tribunal or complain about its cost.

The tribunal has been forced to traipse through the High Court and even the Supreme Court up to a dozen times. It has won more often than it lost, but the loss of time and momentum has been immense. In a game with no give-and-take, opponents have insisted on applying the letter of the law.

For example, in 1998 the Supreme Court found fault with the way the tribunal obtained bank documentation belonging to Bovale Developments, because it hadn't notified all parties concerned. But the court said there was nothing wrong with the tribunal having access to these records.

On this basis, the tribunal asked Bovale and others for permission to retain the files, thus obviating the need to issue further orders for their production. However, this was refused. The tribunal was forced to return the files, and then issue new orders for their production, months later.

The response of many parties to requests for information could be described as leisurely at best. Deadlines came and went, and correspondence flew back and forth. Yet it always seemed that the necessary records arrived at the last minute, before a party's witness was due to give evidence. On other occasions, vast amounts of documentation were handed in, amounting to tens of thousands of documents. Finding a needle in a haystack was judged to be preferable to having no needle at all.

The tribunal first contacted Frank Dunlop in September 1998. Last year he provided them with an affidavit of discovery, saying he had declared all his bank accounts. This wasn't the case, and the crucial AIB account at Rathfarnham Road, the main source of the councillors' cash, only came to light last February. Information about another, hitherto unknown, account emerged only last Tuesday, as Dunlop was being grilled by tribunal lawyers.

This is fairly standard stuff for the people under investigation. Information is drip-fed to the tribunal. Enough is done to fend off accusations of failing to co-operate, which could result in financial penalties. Records and receipts are non-existent, and memories are blank.

Following the "money trail" is crucial to the success of the tribunal. It certainly proved Frank Dunlop's downfall. Yet accountants and financial institutions have played their own role in slowing down the process. So far, we've heard of three different floods that have afflicted places where financial records are stored, and two separate fires.

The performance this week of Michael Fingleton, chief executive of the Irish Nationwide Building Society, is fairly typical. Fingleton seemed to have difficulty understanding the terms of the tribunal's order to produce documents from its Cork branch.

It took him two months to produce a few boxes, contents unknown, until he was pressed further. At one stage, he said the documents had been placed in central storage. Asked where that was, he replied: "Everywhere". No wonder the chairman accused him of having a "cavalier" attitude.

But this is a dirty war and other parties have not shied away from using more irregular stratagems. Fear, intimidation, obstruction, time-wasting and spin-doctoring are the weapons of choice of some of those anxious to keep out of the limelight.

I have heard credible allegations about the intimidation of potential witnesses. Attempts have been made to buy the silence of would-be whistle-blowers. Unsolicited presents have been delivered to people in the hope that they might be persuaded to give evidence critical of others.

Media manipulators tried to kill this tribunal before it was born, then strangle it in its infancy. There were anonymous - and false - claims that James Gogarty would not swear a statement, or was too unwell to give evidence. Later, the selective leaking of confidential documents served two purposes: blackening the name of Gogarty and undermining the credibility of the tribunal.

The same quarters suspected of leaking the information grumbled about the leaks themselves, giving rise to inspired headlines such as "Leaks row threat to tribunal start date".

In February 1999 one newspaper ran a front-page story linking Gogarty to an extortion demand on Michael Bailey, the owner of Bovale Developments. The story was wrong in claiming that Gogarty's name appeared on bank documents relating to Bailey's request for a huge sum of money. Yet it played a major part in colouring attitudes towards Gogarty, long in advance of Mr Justice Flood's final report.

Last week there emerged that inspired insight into the evidence Frank Dunlop was about to give. By then Dunlop, a former Fianna Fail and government press officer, was already on the rack, but this story switched the attention to Fine Gael. Tom Hand of that party was said to have demanded £250,000 from Dunlop in return for his vote on Quarryvale at Dublin County Council. Furthermore, Dunlop was said to have informed the Fine Gael leader, John Bruton, of this fact seven years ago.

Deflecting the blame and spreading the muck are standard tactics used in such situations. With a leading Fianna Fail figure under fire, why not point the finger instead at a Fine Gaeler, and better still a dead Fine Gaeler (Hand died in 1996)?

The ploy was too ambitious, however. Bruton has his critics, but even they would never link him to planning corruption or its concealment. The focus shifted back angrily to Dunlop, who came in for the grilling from tribunal lawyer Patrick Hanratty that led to revelations of payments to 15 councillors.

The spin-doctoring continues. Now that Dunlop has crossed his own personal Rubicon, he, too, is fair game. He only revealed the payments out of a fear of going to jail, we are now told (so why wait until this week to come clean?).

The latest claim is that he failed to pass on all of his client's intended payments to the councillors (well, they would say that, wouldn't they?).

Expect more.

Meanwhile Liam Lawlor, the Fianna Fail TD most often linked to the "gang of 15", twice issued statements denying what had not been claimed. Lawlor was emphatic in his denial that he participated in the rezoning of Quarryvale in 1992, as he was not on the council. Yet he was on the council in 1991, when the first vote to rezone Quarryvale was taken, and this is the period when Dunlop made the payments we learned about this week.

It was Lawlor who secured the most important legal victory against the tribunal, when the High Court last year said he couldn't be forced to attend a private interview with tribunal lawyers. Ultimately, this led Dunlop and others to be summoned to appear in public, having failed to make a statement voluntarily.

One of the fascinations about Frank Dunlop's evidence is that most of what we knew about Quarryvale before this can be traced back to his briefings of key journalists. It was very hard this week to tell Frank Dunlop the witness from Frank Dunlop the spin-doctor. At times, his account in the witness-box seemed to confirm the general state of knowledge you had about the rezoning issue - until you realised that he was only confirming his own spin.

Brazen throughout the life of the tribunal until this week, Dunlop even used the platform afforded him as a host of RTE's Later with Finlay and Dunlop show to cast general aspersions on the tribunal, while steering clear of any discussion on his own involvement in the whole affair.

The element of surprise has led many of us to overestimate the importance of this week. This tribunal has many more hurdles to face. The kind of obstruction that bogged down the Gogarty module of its investigations is likely to surface again.

The middle-men risen from modest circumstances, such as Dunlop and George Redmond, are emerging as the "fall-guys". But the wealthy businessmen and politicians the tribunal was set up to investigate remain largely untouched.

So far.