Defenders of Britain's political system point out that it is less corrupt than many others. No doubt. But that does not mean our MPs have a right to expect any less censure from the public when they are caught with their hands in the till.
From the salary of Derek Conway's son, to Jacqui Smith's home entertainment, the more we learn of how MPs have been exploiting the House of Commons expenses system, the more it looks to the public like a form of corruption. And the stronger the case for reform.
The Committee on Standards in Public Life yesterday confirmed that it will report on Commons expenses before the end of the year. But there is no good reason why this investigation should take so long. The bulk of the abuses that have come to light centres on the so-called "Additional Costs Allowance", which was introduced to fund a base in London for MPs with constituencies outside the capital.
Any reasonable person will recognise that those MPs who need to shuttle between a distant constituency and Westminster on a regular basis need some public financial support, just as those who work in the private sector are entitled to claim expenses if required to travel as part of their job.
The trouble is that MPs have created a system for themselves which is far more generous than those that exist in the private sector. Under the rules MPs can use their allowances to pay the mortgage on a second home in the capital or their constituency. When they leave Parliament they do not hand over the keys of this property to the Commons. It becomes their personal asset. They are also permitted to furnish and maintain such homes at taxpayers' expense.
One obvious solution is to strip the system down and require MPs to claim for daily expenses incurred in staying away from their main home. This is, after all, what those who travel frequently in the business world must do.
But though the solutions seem relatively straightforward, the politics are anything but. MPs have been fighting desperately for years against their expenses being made public. And even now, with the full weight of public opinion behind transparency, they are trying to edit their expense receipts to their own advantage. It is hard to see the impetus for the necessary reform of the system coming from within the Commons.
Yet there ought to be space for radical reform after the next general election when there is likely to be a caucus of new MPs who lack a direct interest in perpetuating the former system. All party leaders ought to commit themselves now to root-and-branch reform of the expenses system.
Clear principles should govern MPs allowances; principles that can be justified in the court of public opinion. If the past few months have taught us anything, it is that the present arrangements utterly fail that test.