Technology in The TES survey.
More than four out of 10 secondary schools are unable to deliver both vocational and academic qualifications post-16.
In a move which will embarrass ministers who want to raise the profile of vocational qualifications, 46 per cent of secondaries admitted they were unable to combine the two routes.
Schools are unwilling to offer general national vocational qualifications and A-levels remain the gold standard, despite attempts by Sir Ron Dearing, chairman of the School Curriculum and Assessment Authority, to correct the imbalance between the two.
John Dunford, immediate past president of the Secondary Heads Association, said the qualifications were too costly in staff terms for many schools which now have serious budget problems.
He said the Government had to give schools the cash they need to introduce GNVQs if ministers are serious about parity of esteem. "Any new initiative needs money to get off the ground," said Mr Dunford, who has had to stop GNVQs at his Durham comprehensive.
"Our GNVQ group had five or six students while the A-level group had 25. We are an overcrowded school, there is terrific pressure on accommodation and we couldn't afford to have a room used by so few students," said Mr Dunford. "Schools are not going to take on courses which they are going to have to subsidise on a permanent basis."
The survey also disclosed that thousands of teenagers are unlikely to receive compulsory lessons in technology this autumn because of shortages of staff and equipment.
More than a third of secondary schools responding to the TES survey said they did not have the equipment or staff to teach technology despite new curriculum Orders.
The disclosure comes just two months after SHA warned that 14 per cent of comprehensives and nearly a quarter of grammar schools believed they would be unable to offer technology to all Year 10 pupils. It said the 14- and 15-year-olds would also miss out on computer lessons, since one fifth of secondary schools cannot guarantee they will be able to offer information technology.
Mr Dunford added: "The survey's findings do not surprise me at all. There are real problems with technology."
The new curriculum Order for key stage 4, covering Years 10 and 11, demands that all students study both technology and information technology. But schools have complained that they lack the necessary resources, expertise and time to introduce it.
Problems with technology start earlier in school life, with 54 per cent of primaries reporting that they have neither the staff nor equipment to teach it. They ease dramatically in middle schools - nearly nine out of 10 of them said they had all they needed - but drop off again in secondaries.
The survey also showed that a quarter of all secondary schools streamed or banded for all subjects and 98 per cent set for some subjects. The most popular subject for setting was maths, followed by science, modern foreign languages and English. A handful of schools said they set for music, history and humanities.