The lack of competitive spirit in school sports is not down to a lack of money, but teachers who don't want to join in and play their part, David Cameron has declared.

The Prime Minister made the controversial comment as he warned there must be "a big cultural change" towards sport in schools if Britain is to capitalise on the Olympic success of Team GB.

He called for a return to the "competitive ethos" in school sports and he hit out at teachers who were unwilling to play their part in coaching and mentoring young talent.

During an interview on LBC 97.3 FM radio, Cameron said while the government was investing £1bn in school sports over the next four years, more needed to be done if Britain was to enjoy continued sporting success in the future.

"Frankly, if the only problem was money, you'd solve this with money. The only problem isn't money," he said.

"The problem has been too many schools wanting to have competitive sport, some teachers not wanting to join in and play their part

"So if we want to have a great sporting legacy for our children - and I do - we have got to have an answer that brings the whole of society together to crack this, more competition, more competitiveness, more getting rid of the idea all must win prizes and you can't have competitive sports days.

"We need a big cultural change - a cultural change in favour of competitive sports. That's what I think really matters.

"And one of the answers there is making sure the sports clubs really deliver in terms of sports in our schools.

"Link the schools with the clubs, because the clubs really believe in competition and the competitive ethos and I think that is one of the best ways to deliver what we want."

Cameron said that while sport had been part of the the national curriculum under the last Labour government, ministers had failed to ensure it was actively encouraged in schools.

"What the last the government did that I think isn't right is if you just simply sit their in Whitehall and set a target but don't actually do anything to help schools meet it, you are not really solving the problem," he said.

"By just saying 'Look, I want you to do this many hours a week' some schools think 'Right, as I've hit that minimum requirement I've ticked the box and I can give up.'"

Cameron acknowledged that since the coalition came to power, 21 school playing fields have been approved for disposal - despite a promise in the coalition agreement that they would be protected.

He insisted that in each case it was because the schools concerned were being closed or merged, the land involved was marginal, or it was for reasons of improving sports access.

"It was a mistake that playing fields were sold in the past. They are not being sold any more," he said.

Sport England chief executive Jennie Price said cash was being spent on encouraging youngsters to play sport and provide the next generation of British Olympians.

She told the BBC: "We invest about £250m a year, a mixture of Lottery and Exchequer - taxpayers' money essentially - into the grassroots of sport.

"People should be very confident that that investment is there and our money is very specifically targeted on participation.

"Our new youth strategy is all about getting young people between the ages of 14 and 25 to play sport regularly."