The poor results could undermine the Government's aim to raise the status of work-related courses and will set alarm bells ringing for the introduction of vocational GCSEs in September 2002.
It is estimated that between a third and a half of the 100,000 students sat exams in the first units of their vocational A-level courses in January, five months after they were introduced as a replacement to advanced GNVQs.
Edexcel, the exam board which has 75 per cent of the vocational qualification market, confirmed that students did very badly in some subjects. In information technology and art and design, less than a quarter of candidates secured an A to E grade. Schools and colleges have also reported that pass rates have plummeted in business and leisure to as low as 10 per cent in some cases. The national average pass rate for advanced GNVQs last year was about 60 per cent.
It is thought that attempts to put vocational A-levels on a par with traditional A-levels may have pitched the new qualifications too high.
Headteachers also blamed the rushed introduction of the new qualification, which caused confusion about what should be taught.
Alan Harrison, principal of Mackworth College, Derby, said: "There is a big disparity between students' work in class and the results. The whole qualification could be undermined if it is not clear why pupils are failing. There is national concern that this could have a terrible effect on students' confidence and progression."
Malcolm Trobe, headteacher at Malmesbury school, Wiltshire, said results from January exams are significantly down on previous years. "The word has got out that these exams are more difficult and this is putting off students. We have gone from having a healthy GNVQ cohort and being in the top 50 schools nationally to an uptake of only two or three students for next year."
Paul Sokoloff, Edexcel director of qualifications, said the exams were more demanding because the Government had made it clear that the traditional A-level has to be used as a benchmark.
"We have had seven or eight years of GNVQ culture which is not going to change overnight. In some subjects, these are tough units. Perhaps teachers are teaching to less than A-level standad," he said.
Multiple-choice tests which were used in advanced GNVQs have been replaced with written answers. The rules governing coursework have also been tightened up. Re-sits are also now in line with A-levels, with students having the option of only one.
Mr Sokoloff said lessons needed to be learnt in the run up to the launch of vocational GCSEs. "The rules governing vocational A-levels were finalised very late so full guidance was sent out late to schools. The shorter the time-scale for introduction, the more likely there that will be problems," he said.
John Dunford, general secretary of the Secondary Heads Association, said:
"These figures give considerable cause for concern to teachers and pupils." But a Government spokesman denied the standard of the vocational A-level was too high.
A spokesman for the Qualifications and Curriculum Authority said it was meeting the exam boards next month to see if any action is required.
Professor Alan Smithers of the centre for education and employment research, Liverpool University, said: "Vocational A-levels have been ill-thought out. They have recast GNVQs in the same shape as A-levels, adding another academic route rather than a good form of practical education for employment.
"The early results seem to show that students are not necessarily able to cope with it. Yet it will still be seen as second best to the old A-level."
Briefing, 22-23; Leader, 18
* A-level Vocational Certificates of Education (VCE) were introduced last September. The full, two-year course is six units (modules). The three units taken in the first year are the equivalent of an AS-level.
* VCEs are graded A to E and exams are externally marked. Centres could choose whether to enter students for the January exam to test the work they have done so far. The main exams are scheduled to take place in June.
* Coursework counts for most of the marks and is internally tested and externally moderated.
* More rigorous testing is a feature of the new qualification which is supposed to bring parity of esteem between the vocational and academic.
* VCEs replace Advanced GNVQs, 12 unit courses, which were the equivalent of two A-levels but seen as an also-ran to the A-level "gold standard".
* Vocational GCSEs are planned for next year to replace GNVQs.