School sixth forms could lose tens of thousands of pounds a year under plans to overhaul the funding system announced this week.
Ministers have signalled they will bring college funding into line with post-16 school funding from 2010. It lags by 5 to 10 per cent.
But schools fear that their funding will take a major hit if, during what is likely to be a period of tight public spending, the Government attempts to achieve its goal without extra resources.
The concern, which has been expressed by the Association of School and College Leaders (ASCL), comes amid problems with the existing funding system.
School sixth forms that are expanding have complained that they will not have enough money to pay for the pupils they are expecting in 200809.
Under the new white paper, the Learning and Skills Council will be scrapped from 2010. Local authorities will take responsibility for distributing the pound;7 billion a year earmarked for 16-18 education in schools and colleges. Councils will work in local groups to commission and fund courses on the basis that "providers receive comparable rates for comparable provision".
School sixth forms receive significantly more than further education colleges for offering exactly the same A-levels and other qualifications. The Association of Colleges calculates that the funding gap amounts to around 10 per cent. But ASCL estimates the gap is no more than 6 per cent.
John Dunford, the general secretary of ASCL, said he was in favour of closing the gap, but not at the expense of funding for schools.
The white paper also proposes giving local authorities the power to cut any school sixth form or college provision that is poor and to expand provision that is good.
Lindsay Wharmby, the ASCL's funding expert, has been contacted by heads across England who fear they will not get the money they need to pay for next year's sixth formers - long before the proposed changes come into effect.
She believes that while there might be enough money in the system, it may have been allocated to the wrong places.
Robert Haylock, head of Chilwell School near Nottingham, said he would have 18 unfunded sixth formers next year - amounting to a shortfall of at least pound;35,000.
"Funding for A-level students has literally been rationed," he said.
The Department for Children, Schools and Families said it had no set date for equalising funding. "Our commitment was to make further progress in closing the gap as resources allow," said a spokesman.
FE Focus, page 1.