If there has been a single, over-riding theme that has characterised British politics over the past decade and a half, it has been the long, slow collapse of public trust in those who govern in our name.
It started with cash for questions under John Major, continued with legislative favours to Labour donors under Tony Blair, and reached a new depth with the dodgy dossiers which sent British troops to war in Iraq on a false prospectus.
After that shameful episode, we probably thought we had seen it all – but the cascade of revelations about MPs expenses over the past eight days has taken public contempt for politicians to a new and potentially dangerous level.
It has truly been a game-changing week in British politics, and for the House of Commons, it is already clear that nothing will ever be the same again.
It began with the publication of the Cabinet’s expense claims last weekend, with Communities Secretary Hazel Blears bearing the brunt of the criticism both inside and outside the Labour Party.
Faced with some stinging rebukes from some of her own colleagues, she later agreed to repay £13,332 in Capital Gains Tax on the sale of her second home, but any slim chance she may have had of becoming Britain’s second woman Prime Minister has probably gone.
This, though, was just the hors d’oeuvres. By the end of the week, MPs were not just paying for their sins by writing cheques, some of them were paying with their jobs.
And it’s not over yet. Andrew Mackay may have been forced to quit as an aide to Tory leader David Cameron, Elliott Morley has been suspended from the Parliamentary Labour Party, and Shahid Malik has temporarily stepped down as a justice minister – but no-one seriously believes they will be the only casualties.
So where does it all leave us? Well, amidst the mayhem, four specific conclusions can so far be drawn.
First, the Tories have been shown by and large to be more greedy than their Labour counterparts, as indeed I suggested might very well be the case on these pages a week ago.
Okay, so Labour has its fair share of Maliks, Morleys and Phil Hopes, all of whom claimed large amounts to cover the costs of their second homes.
But so far as I am aware, neither they nor any other Labour MPs have so far claimed for cleaning moats, repairing swimming pools, mowing paddocks, manuring their vegetable patches, or adding porticos to the front of their houses.
Secondly, though, the past week has also revealed Mr Cameron to be a more instinctive and decisive leader than Prime Minister Gordon Brown.
When confronted with the scale of the problem in his own party, it would have been very easy for the Tory leader to go into defensive mode – but instead, he seized the moment by telling his MPs it was payback time.
His own Shadow Cabinet led the way by repaying more than £17,000 worth of claims on items ranging from chauffeurs to repairing a broken pipe underneath a tennis court.
Mr Brown has defended his more softly-softly approach on the grounds that he is trying to “build consensus” on a way forward - but there is no doubt which of the two leaders has looked more in tune with the public mood.
Thirdly, the affair has demonstrated beyond any remaining doubt that Michael Martin’s nine-year tenure in the House of Commons Speaker’s Chair should now be brought to a close as expeditiously as possible.
I have written previously of his tendency to see himself more as the shop steward for MPs than the guardian of the dignity of Parliament, and events this week proved the point.
Anyone who has followed Mr Martin’s career will know that he has always adhered to a fairly simple philosophy – that whenever anything goes wrong, it is invariably the press that is to blame.
His attacks on backbench MPs who dared to question his decision to mount a leak inquiry over the expenses revelations showed a man out of time, out of touch, and totally out of his depth.
Fourthly and potentially most damaging of all, it is already clear that this episode will have a baleful impact on the public’s attitude to the mainstream parties in the run-up to next month’s European elections.
As senior a figure as Norman Tebbit has already openly called for a “plague on all their houses” vote on 4 June, suggesting only the fringe parties are worthy of support.
Lord Tebbit probably came within a whisker of being thrown out of the Tory Party over his remarks, but I suspect they will nevertheless resonate with large numbers of people.
The UK Independence Party is confident it can beat Labour into fourth place, while more worryingly, the current febrile atmosphere might very well see the election of Britain’s first British National Party MEPs.
I wrote that week the expenses issue was an indictment of the political class as a whole rather than any one individual or party, but nevertheless, it is Mr Brown who stands to be the biggest loser.
It is not as if he couldn’t have seen all this coming. Before it all blew up, the Commons authorities under Mr Martin spent months trying to block a freedom of information request to make MPs expense claims public.
Had Mr Brown been true to his instincts, true to his stated intention to restore public trust in politics on entering No 10, he could have taken the bull by the horns, gone to the papers himself with the information and sacked all the transgressors within his party.
But of course that would have required real leadership. And we now know that this is the kind of leadership which is beyond him.
