In the US, direct contributions from individuals of more than $1,000 to politicians have been banned since the Seventies. Donations of more than $200 in a year have to be published. It may surprise many that contributions from companies and trade unions are banned altogether. It surprised the Prudential insurance company, which was fined $550,000 by the Federal Election Commission last year for fundraising for various candidates in the late Eighties.
But the main effect of this legislation was to channel money through "political action committees", or PACs, which spend money on behalf of candidates while remaining technically independent of them.
The House Speaker Newt Gingrich is supported by a fund called Gopac, which was generously funded by Golden Rule, a health insurance company lobbying against Bill Clinton's healthcare reform plans.
Republican Senator Bob Dole, who hopes to challenge Mr Clinton for the presidency next year, is backed by the Better America Foundation, which was at the centre of a row this summer. "Senator Dole's support for comprehensive telecommunications reform has absolutely nothing to do with contributions to the Better America Foundation," said an aide to Mr Dole, after it was disclosed that telecommunications companies had donated $800,000.
In addition, so-called "soft money" flows into US politics through the political parties' federal and state organisations, which are not controlled by law. This has had the unintended consequence of strengthening the Democratic and Republican party machines, which were deliberately weakened by legislation over the previous century in order to counter earlier corruption scandals.
Mr Clinton was elected President three years ago on a promise to clean up "pork- barrel politics", and he introduced some measures immediately. Journalists were taken aback, for example, to find that all government officials were forbidden to accept hospitality worth more than $25.
Mr Gingrich and his Republican allies were then elected to a majority in both Houses of Congress in last year's mid-term elections on another promise to cleanse the system.
The Republican new right immediately flexed its muscles, bringing Congress members "under the same laws as all other American citizens", ending some of the perks of elected office.
But the debate on the relationship between money and politics goes on. Tighter controls on PACs are often canvassed, but it would be hard to stop third parties supporting candidates. There is a surprising amount of interest, however, in one aspect of the British system - free party political broadcasts. One of the most criticised aspects of the US system is how wealthy interests, through PACs, can buy television advertising time, the nation's most powerful political tool.