The number of graduates gaining teaching qualifications by working in schools instead of attending university courses is to be doubled under government plans announced this week.
But academics fear that extending the graduate teacher programme could reduce teacher training to a craft apprenticeship.
Stephen Timms, the schools standards minister, said he was responding to headteachers' requests to bring more graduates into the programme, which allows schools to employ graduates as unqualified teachers. By combining classroom duties with tailored training programmes, graduates can gain qualified teacher status in about a year.
The new places will offer "training only" grants of £4,000 to be covered by the Teacher Training Agency. Schools will pay the trainees' salaries. "By extending the scheme in this way, there is a real risk that this highly effective programme will be used by schools to fill vacancies," said Rob Foster of the School of Education at Edge Hill College in Ormskirk.
"This could undermine the training of graduate teachers, who will have responsibility for a full teaching load alongside attending training sessions."
He said the graduate teacher programme was in danger of becoming merely a quick remedy for the teacher shortage that could reduce training to little more than a craft apprenticeship.
Mr Foster, who has studied the scheme's effectiveness, said that when places had been fully funded with a £13,000 grant, the programme had attracted new recruits to teaching.
In Lancashire, a consortium including Edge Hill and St Martins College offers training support to graduate teachers. Mr Foster said it was always hard to balance classroom duties and training obligations. He added that with schools paying trainees' salaries, the emphasis could be shifted away from training.