Libby lied to a grand jury, appointed as part of Fitzgerald's investigation into the leaking of the name of a CIA agent by the White House.

That in turn was part of a PR war waged by the Bush administration to justify its reasons for going to war. The CIA agent's husband had cast doubt on tales of Saddam's weapons of mass destruction and therefore had to be taken out. Last week, Libby was found guilty and will now probably go to jail. On Tuesday, Fitzgerald, who has also taken on the mafia, pointed out the importance of the case.

"We cannot tolerate perjury, " he said outside the court. "The truth is what drives our judicial system. If people don't come forward and tell the truth, we have no hope of making the judicial system work."

Fitzgerald is obviously passionate - some would say zealous - about the law, and the importance of its observance if democracy is to mean anything. Good job for him fate didn't find him practising law in the land of his parents.

Perjury in this country is a crime exclusive to the lower orders of society, unlike in the US, or Britain, where Lord Jeffrey Archer was jailed. For 10 years, the tribunals have seen a procession of the great and the good trot in and, on a not infrequent basis, lie through their teeth.

In some cases, like that of the late Liam Lawlor, the evidence was irrefutable (as this column wrote when Lawlor was alive). In others, the evidence is not as clearcut, but I'd bet my bottom-dollar that a Patrick Fitzgerald would find a way to prosecute.

There has not been one prosecution for perjury in the tribunals.

The courts are no different. Lies are told day in, day out, but would usually be difficult to prove. Last July, however, High Court judge Thomas Smyth made a most unusual ruling in a case between Ryanair and some of its pilots. The judge said that, for only the second time in his career, he would have to rule that two witnesses - both appearing for Ryanair - had given "false evidence". He was, in effect, suggesting that, in his opinion, he had witnessed a crime in his courtroom.

The judge's learned opinion may not have stood up to the standard of proof required for a prosecution of perjury but it is surprising that his ruling didn't prompt a criminal investigation.

Won't you come home, Paddy Fitzgerald?

A few weeks after Smyth's ruling, David Smith (21) and 23-year-old Amanda McNamara from Limerick were sentenced to community service for perjury. At a murder trial, both had refused to give evidence in line with statements taken from them earlier. Both were in fear of their lives. Murphy had earlier told garda� that if it came to it, he would rather go to jail.

"I can come out of prison but I can't come out of a box, " he said.

Judge Caroll Moran said six months would be the appropriate sentence as the crime undermined the criminal-justice system. Taking the circumstances into account, he sentenced them to community service.

Perjury is notoriously difficult to prosecute. Yet it beggars belief that the tribunal experience alone has not yielded one opportunity to prosecute somebody for the crime. There isn't the same reluctance in any other jurisdiction with which we are familiar.

In the absence of any such prosecution, the notion that we are all equal before the law is hokum. It is open to anybody with money to go in and chance their arm, secure in the knowledge that if a judge can see through the lies, there is no consequence.

By contrast, if somebody from a dead-end estate comes in and lies blatantly because their lives are in danger, well, an ordered society cannot tolerate that behaviour. Stay where you are, Paddy Fitzgerald. The law on this side of the Atlantic is not as you know it.