Parents should be made to pay for many activities most schools offer for free, says the Government. Children involved in sports coaching, breakfast clubs, play schemes, drama and dance groups will all face charges if schools heed new government guidelines.
The advice to charge will be announced shortly as part of guidance to schools and local authorities on services offered before and after school.
Heads of extended schools, however, said they were appalled by the advice to charge.
Kenny Frederick, head of the George Green school in Greenwich, south London, said: "We were one of the first full-service extended schools and have been implementing all aspects of Every Child Matters for some time with great success.
"It's through offering these extended services for families, along with excellent teaching and learning strategies, that we can really raise standards in our community, but charging for these services is, in my view, unworkable."
Sports bodies were extremely worried about the advice.
A spokesman for the Central Council for Physical Recreation said: "The Government has set itself stretching targets for increasing the number of five to 16-year-olds doing PE and school sport - introducing charges can only be seen as counter-productive."
A Department for Education and Skills spokesman refused to comment on what he described as a "draft" document. Extended schools are part of the Government's Every Child Matters reforms and were originally intended to provide a safety net for children at risk of neglect.
Last year, the Government published an extended schools prospectus, setting out what it expected from them and detailing the pound;840 million of start-up funding it intended to provide. By 2010, all primary schools will be expected to offer childcare between 8am and 6pm year-round, either on-site or in partnership with other schools and local providers. Ministers expect a third of all secondaries to provide activities during the holidays and before and after school by 2008. All secondaries will be part of the network offering 8am-6pm care by 2010.
Ministers anticipate that schools will work with others to offer activities, ranging from play schemes to academic work. But the DfES vision is a world away from the ad hoc arrangements most schools have.
"Many schools already run such activities on a 'drop in' basis. If these can be combined with a formal registration scheme ... then working parents can feel secure about their safety. Such provision can constitute a formal chargeable childcare arrangement, for which working parents may be eligible to reclaim the costs through working tax credit," says the DfES guidance.
Anne Longfield, chief executive of 4Children, the childcare charity, said:
"This is a completely different approach for schools.It's moving the culture of what a school is about to a completely new place."
Ms Longfield pointed out that childcare providers have charged for many years, and that local authorities run holiday playschemes for which parents are asked to pay.
"It's what play and leisure departments have been doing for years; there is an awful lot that schools can learn from childcare providers about how to make this work," she said.
But she acknowledged that many schools would find charging complex and problematic, and that parents might not understand the distinction between study support and childcare.
The DfES guidance sets out the Government's view of the split.
"You may not charge for provision which delivers the national curriculum.
You should charge for childcare. You may charge for some study support activities, such as sports coaching or dance classes, but not for offers relating directly to a child's attainment, such as targeted literacy support."
Many extended schools already offer services free. Some make a token charge for activities such as breakfast clubs. But ministers clearly expect such services will have to be paid for in future.
"Some schools have until now offered free breakfast clubs or subsidised extended services. Although they may feel it is difficult to introduce charges, it is unlikely they will be able to sustain their free offer, once they extend them to become reliable all year round services," says the guidance.
It continues: "In more deprived communities, funding childcare and other extended services through charging will be more difficult. Unwaged parents will not be eligible to claim (working family tax credit). You may legally use your delegated budget to provide free study support places for children and young people facing these barriers."
Working family tax credit, introduced by Chancellor Gordon Brown as a way to encourage more people into work, has a childcare element that allows parents to reclaim 70 per cent of their childcare costs.
The DfES guidance says that the new charges for extended school activities can be reclaimed via this system. But this is just one aspect of the guidance that worries Mick Brookes, general secretary of the National Association of Head Teachers.
"Some working families will be able to claim a proportion of these costs, but those either side of the tax credit boundary will have no entitlement - that worries me," he said.
Mr Brookes was also concerned abut additional responsibilities for his members, and about the risk to the entire culture of after-school voluntary activities.
"Teachers have run activities for years and never expected to be paid for them," he said. "If this goes ahead, the whole tradition of after-school clubs will collapse."
At the Association of School and College Leaders, general secretary John Dunford was equally concerned.
While acknowledging that clear guidance on charging was overdue, he was worried about the grey areas in the guidance.
"Heads are going to have to try to balance extracurricular activities free to any child with extended activities for which the school can charge, but that's not a clear division.
"People support the aims behind all this, but there are considerable concerns about responsibilities and workload, said Mr Dunford."