British Olympic chief Lord Moynihan says funding for sport must increase now if Britain is to meet its goal of coming fourth in the 2012 medals table.
Colin Moynihan believes there is no time to lose
A bid for almost double the current funding for Olympic sports has been submitted to the Treasury.
And a decision could come on Monday in Gordon Brown's pre-Budget report.
"If it is not announced on Monday then we need it by the end of this month. We cannot afford to go into the new year with uncertainty," said Moynihan.
"We need clarity and the funding support for the Olympic programme as soon as possible.
"It is vitally important because governing bodies need to know that the funding will be available for the next six years so they can secure coaches, support staff and identify athletes."
Great Britain finished 10th in the 2004 Olympic medals table, but will be looking to place behind only Russia, China and the USA on home soil.
"Fourth is a realistic target and we said that with the full support of the governing bodies," he said.
"I believe it is attainable but we cannot afford anything to go wrong if we are to meet that target and we cannot afford to lose even six months of preparation."