In a radio interview yesterday McCain said he had not yet made his decision, but that was met with widespread scepticism. He was tipped to reveal his choice at noon today during a rally in Dayton, Ohio, a key battleground state.

The shift in focus to the Republicans, who hold their convention in Minneapolis-St Paul next week, came after last night's Democratic convention finale. The week saw the party unite with the baton of leadership pass from the Clintons to Obama.

Obama's speech at Denver's Mile High stadium came on the 45th anniversary of Martin Luther King's "I have a dream" speech in Washington. Martin Luther King III, the eldest son of the civil rights leader, said: "This is a monumental moment in our nation's history. And it becomes, obviously, an even greater moment in November if he's elected."

The announcement of McCain's running mate is designed to rob the Democrats of any post-convention bounce. Polls published yesterday saw a small rise in support for Obama. McCain planned to make his move just as Obama began delivering his speech with the release of a new television ad which aides described as a direct conversation with his Democratic opponent. More...