Ministers have long been in favour of state schools aping the private sector by instilling military discipline in students. But a scheme designed to encourage more children to don uniforms, learn how to use rifles and yomp across muddy fields has come under fire from the independent schools it set out to emulate.

Leading private schools have described government plans to fund the expansion of Combined Cadet Forces (CCFs) by cutting the funding of existing units as a “disaster” that will lead to closures. Their battle cries have grown louder with the revelation that an additional fee of pound;150 per cadet will be charged to help pay for the scheme, run jointly by the Ministry of Defence and the Department for Education.

Existing CCFs receive significant financial support from the MoD but will face large bills under the new rules. Independent schools, which run 200 of the 260 current units, said that the plans would make their units financially unviable.

The move was outlined in a letter to headteachers by Major General John Crackett, MoD assistant chief of the defence staff (reserves and cadets), who said it was necessary to ensure that the Cadet Expansion Programme established 100 units in English state schools by September 2015. By 2020, the aim is to make the opportunity available to all state schools.

“Schools setting up new [CCFs].agree from the outset to pay a contribution towards the running costs,” writes Major General Crackett. “This has thrown into sharp relief the disparity between new units, which contribute to the public costs of their CCF, and existing units, which do not. My aim is to achieve a funding and charging regime for the CCF that is both equitable and sustainable.”

Major General Crackett said that by charging schools for “an element of the running costs”, the MoD would be able to “expand the essential underpinning training infrastructure and [meet] central fixed costs that support it”.

The funding changes will also affect state schools with existing CCF units, but they will be able to apply for support grants that will not be available to the private sector.

Simon Davies, headmaster of the independent Eastbourne College in East Sussex, which receives a pound;7,000 taxpayer-funded grant for its 335-strong CCF established in 1895, has written to Major General Crackett to complain.

“It is very clear to me that these proposals, and the admirable ambition to extend the CCF to all schools, show a complete lack of comprehension of the real costs of running a CCF and a complete lack of comprehension of just what is involved in establishing a CCF in a maintained school,” he writes.

Speaking to TES, Mr Davies added that it cost his school pound;60,000 a year to run its unit, a sum that could rise to pound;100,000 if the grant were removed and fees were charged.

Thomas Garnier, headmaster of the independent Pangbourne College in Reading and CCF representative for the Headmasters’ and Headmistresses’ Conference, said some private schools would find it “difficult to justify” running a unit. “There will be a net loss of cadets; schools will close units and do leadership and character training instead,” he said. “There will be a loss of awareness of military issues and a dropping of recruitment from our schools.It’s a disaster for the cadet movement.”

Matthew Burgess, general secretary of the Independent Schools Council, added: “The irony is that the participation of independent schools has, until now, ensured that CCF units deliver the best value to the public.”

An MoD spokesperson said it was important to expand CCFs across all schools so that “more young people can develop important life skills such as leadership and confidence”. He added: “To help do this we want to establish an improved, more sustainable funding structure which is fairer for schools, and so many more children can benefit from the skills that cadetship brings.”

The funding changes, which are currently the subject of a consultation with schools, would be phased in over four years, with grants removed by September 2015 and the full pound;150 charge per cadet being introduced by September 2018.