The proportion of 16 and 17-year-olds choosing vocational courses has dropped sharply since 2000, partly because of education reforms which were supposed to promote the qualifications.
Ministers had hoped that changes to the curriculum would lead to more teenagers taking vocational courses alongside traditional subjects.
However, research for the Department for Education and Skills shows that the proportion taking vocational qualifications rose steadily during the 1990s, then fell between 2000 and 2002 from around 42 to 36 per cent.
The latest figure is even lower than that for 1989.
The research concludes that one reason for the drop in popularity of vocational courses was the introduction of Curriculum 2000.
The system split the traditional two-year A-level courses into two separate qualifications: AS, normally taken after one year, and A2, usually taken at the end of the second year. It also introduced Advanced Vocational Certificates of Education (AVCEs), otherwise known as vocational A-levels.
Researcher Joan Payne said the changes made the academic route more attractive to students because they no longer had to commit themselves to a full two years of study.
At the same time, the AVCEs proved less popular than expected, she said, because they were "more similar to academic A-levels than the Advanced GNVQs which they are designed to replace".
Ms Payne said: "These changes in the structure of qualifications almost certainly affected the young people's choices between academic and vocational qualifications.
"It is perhaps surprising that despite the growth of NVQs and GNVQs, the proportion of the age group who were working for vocational qualifications was smaller in 2002 than in 1989."
Another reason for the apparent decline in popularity of vocational courses was a fall in the proportion of students taking part in work-based training, which came as more students stayed in school after 16.
The report was based on surveys of representative cohorts of up to 16,700 teenagers in England and Wales. It found wide geographical variations between the take-up of vocational courses with only 4 per cent of pupils in inner London saying that they were their main study aim compared to 16 per cent in the North-east.
A strong contrast was also noted between comprehensive and selective schools. Even after controlling for GCSE results, pupils at selective schools were significantly more likely to choose academic courses than vocational qualifications at 16.
Phil Willis, Liberal Democrat education spokesman, said that the proportion of young people with vocational skills would drop even lower unless there was radical change to the curriculum.
The figures showed that the Government's drive to improve teenagers'
vocational skills was being undermined by its campaign to get more young people into higher education, he said. Teenagers recognised that they stood a greater chance of attending university if they took the academic route.
"Students see vocational A-levels only as pale imitations of the gold standard qualification," Mr Willis said.
A government spokesman denied Curriculum 2000 was affecting vocational courses adversely. She said: "Raising the standard of vocational education on offer to pupils is one of the key elements that Mike Tomlinson's review will look at. We have already introduced popular vocational GCSEs including engineering and applied science."
FE Focus 1
Vocational Pathways at Age 16-19: An analysis of the England and Wales youth cohort study is at www.dfes.gov.ukresearch