From May 9th online issue of the Daily Telegraph:

Mr Obama, who is already developing his campaign against the Republican nominee, Senator John McCain, gave every indication that May 20 would prove a red letter day after nearly 16 months of campaigning.

"I think we [could] make a pretty strong claim that we have got the most runs and it's the ninth inning and we have won," he told NBC television, referring to the final phase of a baseball game.

"But, you know, I think it is also important for us to, if we win, do so in a way that brings the party together."

Privately Mr Obama's campaign staff insisted that some kind of declaration will be made on May 20, when 103 delegates are up for grabs.

By then, they fully expect him to have 1,627 pledged delegates – 51 per cent of those available.