Further education college chiefs and union leaders have warned that government plans to draft further education lecturers into schools will drain colleges of their most valuable teachers.
Estelle Morris, the education secretary, wants to scrap rules banning lecturers from being employed by schools, so that they can help boost vocational studies in the classroom.
College heads have said that while there is nothing wrong with the proposal in principle, in practice it is likely to lead to more lecturers finding permanent posts in schools, where they can earn up to 10 per cent more for doing the same job.
The Association of Colleges warned this week that such a move could mean a "dramatic" loss of lecturers in vocational subject areas where there was already a shortage.
Sue Dutton, the AoC's deputy chief executive, said: "It's a double-edged sword. Obviously, it's great for lecturers to be able to take advantage of new arrangements with schools and broaden the scope of the work they do.
"But there is an important counter-argument that it will further heighten lecturers' awareness of differences in pay and conditions between colleges and schools, and dramatically increase the flow of lecturers from colleges to schools."
Ms Dutton said colleges were already suffering a turnover of up to 20 per cent a year in teaching staff with specialist vocational skills.
Colleges could not hope to keep pace with pay rises in schools because they were still implementing annual efficiency gains, she said.
"It's difficult to see how colleges will manage if that gets any worse," she added.
Sue Berryman, head of further education for Natfhe, the college lecturers' union, said lecturers were likely to be tempted into schools because although they had the same percentage pay increase as teachers this year, it was from a lower average salary.
"The government might think this is a way to solve some of its problems in schools, but it will be no good if it simply moves the problem over to colleges," she said.
* Unions that make up further education's National Joint Forum, representing lecturers, support staff and managers, have agreed to submit a common-core pay claim to employers next year.
The AoC said the move was part of an effort to create common conditions of service for all further education staff.