David Cameron is facing furious backlash from teachers after he criticised staff for refusing to play their part in running school sports.
The Prime Minister warned there would have to be a "big cultural change" in schools if Britain was to build a successful sporting legacy in the wake of the London Olympics.
His comments drew an angry response from teaching unions who pointed to cuts to the School Sport Partnership and the continued sell-off of school playing fields, despite coalition promises that they would be protected.
The row erupted as it emerged that ministers had ditched a target introduced by the former Labour government for all state school pupils to take part in at least two hours of PE and sport a week.
Cameron defended the decision, arguing that Labour's approach had been counter-productive.
"If you just simply sit there 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 told London's LBC 97.3 radio station.
"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.'"
"Frankly, if the only problem was money, you'd solve this with money," he said.
"The problem has been too many schools not 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."
His comments were branded "foolhardy" by Christine Blower, general secretary of the National Union of Teachers, who said he failed to realise that he was "the architect of a worsening situation".
"It's not because of teachers that funding for the School Sport Partnership has been so drastically reduced," she said.
"What we need is the support of Government, not the shifting of blame. We know of many teachers who are spending time from their summer break taking children from their schools to the Games."
Chris Keates, general secretary of the NASUWT teaching union, said it was "unfair" to blame schools for failing to foster a competitive spirit.
"The real issue is the major cuts that this coalition Government has made to school sports. They have cut school budgets in real terms, which has reduced the resources available for schools to spend on sport," she said.
"By ratcheting up the high stakes school accountability regime, ministers have forced schools to focus on a narrow core of academic subjects, which has reduced time in the curriculum for PE."
Malcolm Trobe, deputy general secretary of the Association of School and College Leaders, said school sports needed the right facilities and funding to flourish.
"Obviously, the selling off of playing fields by both major political parties has not been a good step," he said.
"I think it's a bit rich to make a comment like this when one of the most successful schemes was the work done by sports colleges and school sports partnerships, and two years ago that funding was removed by the current Government."
British Olympic Association chairman Lord Moynihan said that while different teachers had "different agendas", there were many who did get involved in sport and who deserved support.
"It is right some would not choose to stay on after school to teach sport but there are a lot that would," he said. "We need to give them the tools to do the job - the time and the facilities."
Cameron acknowledged that since the coalition came to power, 21 school playing fields had been approved for disposal - but said 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.