More than a quarter of students joining "vocational A-level" courses in 1994 have either dropped out or made no progress, it emerged this week.
Figures released by the Joint Council of National Vocational Awarding Bodies show that 20,901 out of 74,428 - 28 per cent - of students registered for Advanced General National Vocational Qualifications programmes two years ago had not even taken one unit towards the full 12-unit award by July this year.
Nearly half of the total registered had failed to gain half an Advanced GNVQ - deemed equivalent to an A-level pass.
The council said it expected that at least a fifth had dropped out due to difficulties in coping with the course, financial or personal problems, or a decision to transfer to another programme or take employment.
The news cast a shadow over GNVQ successes announced on Tuesday which, following impressive A level and GCSE passes, were declared a "results hat-trick" by Gillian Shephard, secretary of state for education and employment.
Alan Smithers, director of the Centre for Education and Employment Research at Brunel University, said the figures had been presented in a "sleight of hand" fashion.
A declared 79 per cent success rate in students gaining at least half an Advanced GNVQ was based this year on the number of candidates tested. Numbers registered for courses had dropped out of the statistics.
A spokeswoman for the council admitted that the dropout rate was still "an issue", but said it had been decided not to include registrations in the figures because they could be misleading.
"The point is that GNVQs do not have to be completed within a set time, so students are able to gain an award over a longer period," she said.
However, Mrs Shephard made it clear she expected most Advanced GNVQ students to gain an award within two years. "I would expect them to complete within two years whether they are in further education or in schools, because that is the expectation of the course," she said.
Mrs Shephard said GNVQ results were improving, but there were still areas which needed strengthening. There was also a need to cut back on the "confusing plethora" of qualifications, awarding bodies and examination boards, to keep a closer watch on standards.