I am instinctively against the form of retrospective justice being applied to MPs' expenses. Sir Thomas Legg's review seems to have pandered to what Harriet Harman chillingly described as "the court of public opinion". (The court may be with the left on bank bonuses but it also supports capital punishment. I'd rather a precedent wasn't set.) Britain should be governed by the rule of law, not by panic inquiries and the whims of public opinion.

But the debate over the legitimacy of Legg's measures has largely ignored the question of how MPs can restore their reputation. If anything, the repayments only remind voters of the original abuses.

The most egregious offenders, Anthony Steen, Margaret Moran, Douglas Hogg and Elliot Morley, may have something to learn from John Profumo. Profumo, secretary of state for war under Harold Macmillan, was forced to resign after admitting that he had lied to parliament over his affair with the call girl Christine Keeler. His departure destroyed the public's belief in the moral superiority of the ruling class and paved the way for Labour's 1964 election victory.

But after his withdrawal from politics, Profumo refused to display any anger or greivance over his decline. Instead, he dedicated the rest of his life to good works at Toynbee Hall in the East End of London. He began as a volunteer cleaning toilets and later served as the charity's chief fundraiser. A man whose name had become a byword for scandal and disgrace became equally synonymous with philanthropic endeavour.

Profumo, with his long atonement, is now more esteemed than many of his contemporaries. Should MPs wish to demonstrate that contrition is more than a financial transaction they should follow his example.