Vocational education is being used to "warehouse" low-attaining pupils before "spewing them out" on to the dole queue, according to a leading expert on the sector.
Professor Geoff Hayward, head of Leeds University's school of education, said that although the courses are often interesting to pupils, they can be of little long-term benefit.
Pupils could progress to universities with vocational qualifications, he said. But, on average, research showed they attended less prestigious institutions and had higher failure and drop-out rates than those with "so-called academic" qualifications.
Professor Hayward's comments come in the run-up to next week's VQ Day celebrating the importance of vocational qualifications, and at a critical time for their future.
The Government is consulting this summer on which vocational qualifications should continue to count in school league tables, in response to the Wolf report on vocational education.
Professor Alison Wolf's Government-commissioned review reported an explosion in their use since 2003 because of GCSE equivalences that they did "not necessarily" deserve.
Coalition sources have claimed millions of pupils have been "pushed into dead-end qualifications".
Last week Ofsted questioned the GCSE equivalences given to vocational business studies qualifications. The watchdog said even pupils achieving good results on the courses had weak levels of understanding.
Professor Hayward, speaking at a Cambridge Assessment seminar on 14-16 education last week, said: "We have to a great extent, at least in economic terms, used the vocational education and training system to warehouse those (lower-attaining) young people in the education system to spew them out later on to swell the growing ranks of the youth unemployed that we see today.
"We seem to be able to provide learning programmes that they find interesting, but it may not be in their long-term interest to follow those programmes."
He said England's education system wrote pupils off as "not so bright" too often, and contrasted it with Norway, where he was able to talk to pupils with special educational needs in English.
Professor Ken Spours, from London University's Institute of Education, told the seminar that league table equivalences had helped raise the aspirations of mid-ability pupils without equipping them to succeed at the next level.
"Young people with just a Btec and one GCSE want to take A-levels" he said. "Of course they are going to struggle."
Professor Spours claimed such pupils were a "squeezed middle" who would now be "hammered away at" by Coalition ministers as they focused on the academically able.
"This Government actively talks down middle-road qualifications," Professor Spours said. "It says they are useless and then expects young people to take them when they can't go into other routes."
A Department for Education spokesman said: "There are plenty of good vocational qualifications - those that lead to higher education or a good job. But Professor Wolf's report highlighted the sad fact that thousands of young people take qualifications that do not lead anywhere."
ON THE RISE
The number of key stage 4 vocationally related courses has "exploded" in schools, with a 24,458 per cent increase since 200304, according to the Wolf review of vocational education.
That year saw 1,882 such qualifications achieved by school pupils, compared to 462,182 in 200910.
Professor Alison Wolf said there was no evidence to support claims that such courses helped motivate pupils in other subjects.