Two days after receiving the backing of former US Secretary of State Colin Powell, Democratic presidential candidate Barack Obama has received the backing of another politician who might have been expected to support his Republican opponent John McCain - London's Conservative mayor Boris Johnson.

Defying the unwritten rule that politicians don't interfere in other countries' elections, Mr Johnson told readers of the right-wing newspaper The Daily Telegraph that Barack Obama seems "highly intelligent" and that "unlike the current occupant of the White House, he has no difficulty in orally extemporising a series of grammatical English sentences."

Mr Johnson went on to say that he is not suggesting that John McCain "is a buffoon, or that Obama is quite as Messianic as some of his supporters seem to believe. But then again, he is patently not the Marxist subversive loony Lefty that some of his detractors allege."

"Best hope"
Referring to Mr Obama's race, Boris Johnson said that "If Obama wins, he will have established that being black is as relevant to your ability to do a hard job as being left-handed or ginger-haired, and he will have re-established America's claim to be the last, best hope of Earth."

Turning his attention to President George Bush, Mr Johnson said that he has pulled off an "astonishing double whammy" of wrecking both democracy and capitalism through the Iraq invasion and the collapse of the banking system. "To have rocked one of those pillars may be regarded as a misfortune. To have damaged the reputation of both, at home and abroad, is a pretty stunning achievement for an American president."

Eccentric
Mr Johnson's remarks are not likely to have much impact in the United States. Although Boris Johnson has a high profile in the UK, partly through his appearances on TV panel shows, his main claim to fame abroad is the Olympic handover ceremony a few months ago, when his less than immaculate appearance and typically eccentric behaviour bemused the Chinese and embarrassed his British compatriots.

But his comments will undoubtedly have annoyed the Conservative Party, in particular its leader David Cameron who praised Senator Obama's Republican rival John McCain earlier this year. The British Conservative Party traditionally supports the Republicans, and Senator McCain spoke at its annual conference two years ago.