Boris Johnson today broke political convention by backing Barack Obama for President of the United States.
The Mayor said an election victory for the Democrat senator would be a "fantastic" boost for black people everywhere.
His remarks break the convention that politicians do not become involved in other countries' elections. They also threaten to put Mr Johnson at odds with Tory leader David Cameron who praised Mr Obama's Republican rival John McCain earlier this year.
The Tories have traditionally supported the Republicans and Mr McCain spoke at the party's annual conference in Bournemouth two years ago.
Mr Johnson said an Obama win could boost the self-image of young black Londoners. In an interview for the August edition of Square Mile magazine, he said: "John McCain has many, many wonderful qualities, but I think a Barack Obama victory would do fantastic things for the confidence and the feelings of black people around the world."
Asked whether his words constituted an endorsement, he replied: "Yes."
While Mr Cameron met Mr Obama on his visit to London last weekend he has also held talks with Mr McCain, who described him as a future Tory JFK.
