Funding cuts expected to be announced this week could hit Britain's medal hopes at the London 2012 Olympics, it was claimed.
As much as £100m in private sector investment out of a £600m pledge to the Olympic team has failed to materialise. A UK Sport board meeting tomorrow will decide where any cuts may have to be made.
An increase in anticipated Lottery ticket sales has reduced the £100m shortfall to £79m but it could still potentially take the shine off Britain's target for fourth place in the 2012 medals table.
Lord Moynihan, the British Olympic Association chairman, called on Prime Minister Gordon Brown to honour his original 2006 commitment of £100m a year for Olympic sports.
Lord Moynihan said: "To give our Olympic and Paralympic athletes the best chance of success in 2012, the full investment programme agreed by Gordon Brown when he was Chancellor must be honoured in full."
It is believed that various funding packages are being looked at.
If other streams of funding could not be arranged, Hugh Robertson, shadow sports and Olympics spokesman, said he could imagine "in extremis" that the shortfall may be plugged from the Olympic contingency.
He said: "I think there is no option but to take it out of the contingency because to field a substandard British team at the London Olympics is unacceptable."
Team sports could be more at risk as they are seen as more expensive to fund than individual sports.
Handball is a developing sport with increasing participation levels in Britain but it has little chance of a medal at the 2012 Games. They are hoping for an eighth place finish at the London Games.
Alternative training plans in case of a funding cut are already being discussed.
British Handball Association spokesman Paul Bray said: "We have to be realistic. We have to be pragmatic because whatever we face (once funding is decided) is the reality of the situation.
"You cannot by any means maintain the momentum if we lose the funding, but we must not overlook what we have achieved so far because we have achieved so much."
The Department for Culture, Media and Sport (DCMS) insists there will be more money for London than there was for Beijing.
A DCMS spokesman said: "There was a record amount of public funding for Beijing, helping our Olympians' and Paralympians' fantastic performance in finishing fourth and second in the medal tables respectively.
"The public funding package for elite athletes for London 2012 will be more than Beijing, and we are continuing to work hard with UK Sport and Fast Track to raise additional funding from the private sector in a tough economic climate."