The Modern Apprenticeship will fail unless the Government keeps a tight rein on the standards companies offer, University of Sheffield researchers warn.
The warning comes in a study of the scheme's pilot year and is the most detailed examining employer uptake of the initiative, launched as a new deal for youth.
A study of the first 700 modern apprentices shows that nine out of 10 were white males. Trainees with disabilities (3.3 per cent) were under-represented.
Recruitment was weighted towards those of above average academic ability. One in six had already achieved a vocational qualification, reducing the pressure on employers to train from scratch.
The research finds little evidence that the Modern Apprenticeship is helping a wider ability range than before. School and college leavers are not assured high-quality provision, according to researchers Lorna Unwin and Jerry Wellington.
"Some apprentices have been taken on by prestigious companies such as Rover and British Steel, which offer them the chance of studying to degree level. Others have been less fortunate.
"In chemicals, whilst apprentices have been told they were sponsored by a well-known company, they were in fact employed by the training provider administering the apprenticeship."
Their concern about the lack of a clear qualification structure or training guarantee has alarmed other critics, including the National Institute for Economic and Social Research and the Manchester University Centre for Education and Employment Studies.
Both support Sir Ron Dearing, who is understood in his review of 16 to 19 qualifications to be pressing for the whole of youth training to be covered by national traineeships. These would come within his planned national qualifications framework.
Neither the national vocational qualification nor the general national vocational qualification are thought not to fit the bill.
Professor Alan Smithers, from the Manchester University centre, says the NVQ should be widened to include more than just the present competence testing of skills of people in work.
"We need a new approach for those who have not yet got a job but want to improve their chances of getting one, while not closing doors on the other options. They would be guaranteed programmes of study to cover their broader needs and an assurance that employers will give them specific skills training. "