Had the blanket coverage continued for another few days, Browne implied, it might have provided a distraction for people.

Another cynic remarked that Ahern's recent experiments with his hair, which he changed from statesmanlike grey to a blonder tint that made him look like a menopausal Paris Hilton, were a ruse to distract us from his frankly incredible evidence before Mahon. If so, it didn't work.

(Apologies, by the way, to Pat Rabbitte for the blatant theft of his carefully crafted simile. ) It's hard to know yet how the Taoiseach's evidence will go down with the electorate. If you were to judge simply by texts and calls to radio shows, you would say that people were very engaged with the story and not greatly enamoured of the Taoiseach's evidence. If you were to listen to some of the vox pops done on the streets of Ireland, however, you might come to the opposite conclusion. One such survey, done by Newstalk in Drumcondra in Dublin, was as great a display of wilful ignorance as was ever heard on Irish radio.

The consensus was that in hoovering up cash donations in the 1990s, the Taoiseach was merely engaging in the common practice of the time, a blanket justification for bad behaviour which would excuse everything from tartan mini-skirts to the raping of children by Irish priests in the late 20th century.

Whatever about people being distracted from the work of the tribunal over the last week, there is no doubt that the level of coverage given to the Taoiseach's evidence, both before and during his appearances in front of Judge Mahon, has provided a distraction from perhaps the most important political story since May's general election . . . the collapse of the credibility of the Green Party. The party had been balancing on the precipice of plausibility anyway, after agreeing to go into government with Fianna Fail in return for virtually nothing in the way of environmental policy. But since the formation of the cabinet, the enthusiasm with which John Gormley and more lately Eamon Ryan have ditched core Green policy in a variety of areas has rendered their party a pitiable defender of the environment.

There is no point in rehashing the cynicism with which Gormley accepted the destruction of a national monument near Tara, or his timid retreat from his party's previously expressed policy on incinerators, or his decision to issue licences for hare coursing. These have been well and widely reported. Much more interesting is his inability to come to terms with what it means to be a minister.

Having taken the job because, he said, it allowed him to implement policy, he has spent much of his time in office explaining to people what he can't do. He can't do anything about Dick Roche's decision to destroy the monument at Tara; he can't say anything about the incinerator in Ringsend. In fact, he has said nothing interesting about anything since being appointed. Instead, he has become a Fianna Fail rubber stamp, perpetuating the outrages of yesteryear.

The one thing he has done that you might argue was consistent with his previously expressed beliefs was his decision last week to approve fees for 100,000 on builders applying for permission to build large-scale developments such as motorways and power plants. In fact, the sum is minuscule relative to the massive profits developers will make from such projects; Gormley's approval of the fees was a mere token gesture.

Ryan has fared little better since appointed Minister for Communications. His announcement last weekend that he was in favour of the EU Treaty on which Ireland will vote in a referendum next year immediately put him at odds with his party, which has been a consistent opponent of such treaties. Ryan put his support for the treaty down to the way the EU has benefited Ireland environmentally, economically and socially, although those benefits were presumably as obvious the last time we voted in an EU referendum . . .when the Greens were urging a no vote.

In fact, it would be interesting to know how Ryan voted in all those previous referendums. Did he vote no, as mandated by party policy?

Or did he tick the yes box while urging the rest of us to do the opposite?

In any event, it seems likely now that the Taoiseach is enthused about having the Greens in government because, as former Green MEP Patricia McKenna has suggested, he wants to neutralise opposition to the treaty. It's certainly not as a result of any sudden conversion to environmental causes. Once again, we see Green ministers in the role of rubber stamps.

Since becoming ministers, both Ryan and Gormley have dealt briefly with the accusations of u-turns and sellouts. Gormley has argued that he is in government principally to help deal with climate change, which he believes is the single biggest challenge facing the world today. The problem for the minister is that the vast majority of people are not as sure as he is of that being the case.

In any event, Ireland's carbon emissions are so minuscule . . . relative to the rest of the world . . . that any achievements Gormley claims in this area won't amount to very much.

In fact, you could argue that if he was really so worried about climate change he would have stayed in opposition, where he would have had much more scope, time and opportunity to campaign on the issue.

Ryan has spoken about the sacrifices that have had to be made to achieve power, but in reality, that pain has been suffered by ordinary Green party members and voters who thought they were electing ideological and committed politicians but ended up with grubby opportunists.

The anxiety of both Gormley and Ryan to get into government, and the u-turns they performed to achieve ministerial status, show them to be two ambitious politicians who years ago identified a growing public interest in the environment as the vehicle that would propel them to power.

Now that they are there, they feel confident enough to say goodbye to the old ways. It's enough to drive you to distraction.