Gordon Brown has faced renewed calls from industry leaders to increase investment in tourism, ahead of next week's Comprehensive Spending Review.
The Government has announced that the Review, which will set out departmental spending for 2008-2011, will be published on Tuesday afternoon.
Publishing its annual review today, VisitBritain added its weight to calls for the Government to increase investment in tourism to ensure the predicted £2.1b benefit of the 2012 Olympics are realised.
Chairman Christopher Rodrigues said that while the Government will spend £9b staging the Games, it has yet to promise a penny more to secure UK tourism's legacy.
"We've got the vision to leverage the 2012 Olympic Games over a decade of opportunity and help transform Britain's £85b visitor economy," he said.
"But we have reached the point where there is no slack: without increased funding we will not be able to deliver the work required to ensure an Olympic legacy."
The Tourism Alliance has previously published figures showing VisitBritain's overseas marketing budget of £35.5m has been static for a decade, despite tourism benefiting the UK economy by £1b a year.
Last month, industry leaders expressed disappointment that the Government's official strategy document detailing how tourism could benefit from the 2012 Games did not contain any details of funding.
By Daniel Thomas