The introduction of performance-related pay will make the recruitment of teachers resemble the "football transfer window", with schools forced to outbid each other for top talent, experts have warned.
Schools given freedom to set their own pay levels for teaching staff will end up being forced to pay premium salaries to attract the best teachers, particularly in shortage subjects, speakers at a London seminar on performance-related pay for teachers claimed.
Tom Hadley, director of policy at the Recruitment and Employment Confederation, told the Westminster Education Forum that the abolition of automatic rises and national pay scales in England this year would lead to schools having to outbid each other.
"It's having an impact on teacher retention," he said. "We're already seeing a real challenge with the shortages in certain [subjects]. In terms of the market, I think we will start to see things evolve.schools are giving more money to certain high-demand roles and less to others, almost like we're seeing a football transfer window start to [emerge]."
Jonathan Simons, head of education at right-leaning thinktank Policy Exchange, told the conference that teachers of science, technology, engineering and mathematics who moved between schools were increasingly demanding higher salaries. "They know their worth, and they are not afraid of mentioning it [in job interviews]," he said.
Performance pay will be introduced for teachers in England from September, after experiments with the policy in other countries including Sweden, Portugal, India and parts of the US.
Mr Simons also argued that students should be allowed a say in setting the pay of teachers. As reported by TES, a study by the Programme for International Student Assessment (Pisa) shows that nearly two-thirds of the world's 15-year-olds are asked to give written feedback on the performance of their teachers.
"I don't see in principle, if it's properly controlled, why you wouldn't want to have some element of pupils' views, even if it's not binding, as part of the appraisal process," he said.
But Darren Northcott, national official for education at the NASUWT union, expressed reservations about students' views affecting teachers' pay rises. "Because they are sensitive issues and can have legal consequences as well, I think a formal role for pupils.is rather complex and could really give very young people responsibilities which it would be very unreasonable for them to bear," he said.
Steve Fairclough, head of the independent Abbotsholme School in Derbyshire, told the seminar that he had implemented a flexible system of performance pay that allowed him to pay some high-performing classroom teachers more than their line managers.
Teachers were paid according to their "value to the school", he said. This allowed him to "keep my best teachers in the classroom, rather than [them] becoming deputies or headteachers and not teaching".
"Somebody teaching in a department could be more valuable to the school than a head of department," he added.