Caborn warned that the success of the Commonwealth Games in Manchester was no reason to launch an Olympic bid.

"The Commonwealth Games have shown that Britain can stage top-class events on the world stage," said Caborn.

"No one can any longer doubt our ability to deliver. But to bid for the next event just because the last one was good is a recipe for disaster.

"Let's not get carried away on the emotion of the moment. Events have to be assessed on their merits.

"That's why, from now on, this Government is only going to commit itself to supporting bids for those mega events after a thorough and independent assessment of all of the costs, of the benefits we get in return, and of the risks involved.

"We will also insist on knowing, before any decision is made, who is going to be responsible for delivering the project.

"It costs a substantial amount of public money to put these events on, and it would be irresponsible if we did not make those assessments as thoroughly as possible.

"We must never get into the situation we had with the 2005 World Athletics Championships again.

"And the way we avoid it is by doing that rigorous work up front, before any of us commits to stage an event."