London 2012 officials have revealed that building work on the Olympic Stadium will start three months early.
Work on the Olympic Stadium was scheduled to begin in July 2008
David Higgins, chief executive of the Olympic Delivery Authority, told BBC Radio 4 that construction would now get under way in April or May 2008.
"The quicker we start the more time we have to ensure completion in an effective time to allow the test events to happen in 2011," he said.
The design of the £496m stadium will be officially unveiled on Wednesday.
The 80,000-seater venue was originally expected to cost £280m when London set its budget in 2004.
But that figure has risen dramatically, chiefly because of inflation and the fact that VAT was not factored into the original bill.
Higgins added that he was confident there would be no further rise in building costs.
News that the stadium work will begin ahead of schedule comes just a week after International Olympic Association president Jacques Rogge urged London organisers to step up their plans in order to deliver the Games on time.