Professor David Raffe, a member of Mike Tomlinson's task force reviewing 14-19 education, told MPs this week that were he in power, he would bring in immediate legislation.
Professor Raffe, director of Moray House school of education at Edinburgh university, said: "I would be happy if I could legislate tomorrow that it would not be legal to employ somebody below the age of 18 without offering training to back it up."
He was responding to a remark from Barry Sheerman, chairman of the Commons education select committee which is investigating the 14-19 strategy, about the large number of English teenagers who leave education without qualifications. Mr Sheerman said he was delighted by the professor's reply.
Professor Raffe warned the Government's drive to get half the population into university could damage the prospects of the rest and said 14-19 education currently was not joined up.
He said any new qualifications would fail if it was not easy to understand and called for a system catering for all levels.
Professor Raffe said: "I would not put such an emphasis on getting so many into higher education compared to the other things that could be achieved.
I would not want the design of the vocational components to be distorted by this preoccupation with higher education.
"I dispute the idea we bend policy purely to reach a higher education target for young people if that means poorer provision for the other 50 per cent."
He said the challenge was to achieve genuine employer ownership of courses which were understood by all.
Professor Raffe said Australia, New Zealand and Ireland offered good examples of vocational education but warned against directly importing a foreign system due to cultural and social differences.
He would not say at what age vocational training should start, but said it should be of secondary importance to getting core skills like reading and writing for under-16s.