Vocational A-levels are failing to provide young people with the skills they require in the workplace, according to inspectors.
A report from the Office for Standards in Education found that take-up of the Advanced Vocational Certificate in Education (AVCE) was low and the qualification was badly designed.
The AVCEs, which replaced advanced General National Vocational Qualifications under Curriculum 2000 reforms, were "neither seriously vocational nor consistently advanced".
David Bell, the chief inspector of schools, said: "Action should now be taken to increase the vocational skills component of most AVCE courses and make work experience a mandatory course requirement."
He said that the Qualifications and Curriculum Authority should review the specifications of the courses and teachers should be allowed to set more imaginative assignments.
The report said most of the teaching of the new qualifications was satisfactory or good. However, the proportion of unsatisfactory teaching, at 13 per cent, was higher than average for 16-19 education.
The AVCE's aims were not clearly understood by many teachers and students, the study found, and some subjects lacked workplace elements. They were also criticised for being too similar to academic A-levels.
While the teaching of information and communications technology was usually effective, that of number and communication was poorly integrated into courses and "generally unsuccessful".
The report, which analysed the first two years of vocational A-levels, found that students spent too much time being tested.
Inspectors, who visited 45 FE and sixth-form colleges, and nine secondary schools in England, said staff often lacked recent industrial experience.
The report was based on inspectors' observations of eight vocational A-levels - science, construction, engineering, business, ICT, travel and tourism, health and social care and art and design.
A Department for Education and Skills spokesman said the exams were being redeveloped and from 2005 will have the ASA2 structure which should encourage take-up.
"These are promising signs of growth - there has been 25 per cent growth in numbers taking AS and A-level VCEs in 2003. And many students are taking mixed programmes alongside A-levels," he said.