British lectures to foreign governments are now laughed at from the Middle East to the Caribbean, as foreign newspapers print stories about MPs' expenses claims.
Reports of MPs billing the taxpayer for fake mortgages, duck houses, trouser presses and moat cleaning pose a problem for British diplomats who have previously criticised foreign corruption.
The Foreign Office minister Mark Malloch-Brown deleted part of a speech he gave in Mozambique this month, out of fear that comments on standards of governance might be ridiculed.
In a speech broadcast after the disputed presidential elections, Ayatollah Ali Khamenei, Iran's supreme leader, said: "Many countries of the world, including western countries, that claim to fight corruption and money-laundering, are corrupt to their core. You have all heard about the expenses scandals in the British government and the parliament. The whole world heard the story and those were just parts of the story."
It has also hindered attempts to stamp out corruption in the Turks and Caicos Islands, a British overseas territory with a population of 32,000.
Ministers were preparing to suspend the islands' constitution and dissolve its parliament after an official inquiry found signs of "systemic corruption" and "political amorality". But now Galmo Williams, the islands' premier, says British politicians "no longer have the moral authority to lecture other countries on corruption".
This problem won't go away until after the next general election, but at least the British government have Silvio Berlusconi to make them look good.