This is because the alternative to private donations is public ones – in other words, state funding of those parties and politicians. To spell it out, that means you, the taxpayer, being forced to pay for them, politicians and parties. This is wrong in principle. There is no case for readers of this site being compelled to subsidise Ed Miliband, or readers of LabourList David Cameron, or readers of LiberalDemocrat voice either of them – or any combination you like. For “readers”, also read “voters”. If Miliband or Cameron or anyone else want money, they should persuade rather than force people to give it to them. What can possibly be wrong with that?

In practice, however, there is a strong argument for parties, when it comes to taking donations, going further than the rules require them to do. This, the third day of reporting of stories about political donations to the Conservatives, helps to illustrate why.

Andrew Feldman has done an exemplary job of turning round the Party’s finances to the point where it is now debt-free. (He was appointed Party Chairman because he is a mate of the Prime Minister, which wasn’t satisfactory, but has turned out to be a better politician than many of those in Cabinet, which certainly is.) And it is true that runs of stories about parties and money – be it business donations to the Tories or union ones to Labour – come and go.

It is also true that the cases of the two parties are different. If a single business figure had the grip on Conservative policy and candidates that Unite has on Labour, you would never hear the end of it in the Guardian and the BBC.

None the less, the drip-drip-drip of stories about big donations to the Conservatives is corrosive. They help to reinforce the Party’s principal reputational weaknesses – namely, that it is the Party of the rich. Nothing would be more likely to turn that reputation on its head than the announcement that it will no longer each year take donations from a single person or business worth more than, say, £50,000. This is not a change that could realistically be made during the run-up to an election. But it is one to aim for during the years after.