Capping headteachers' earnings to the prime minister's salary could lead to more heads being awarded large pay packets, the head of the independent body in charge of teachers' pay has warned the Education Secretary.
Dr Anne Wright, chair of the School Teachers' Review Body (STRB), has written to Michael Gove suggesting that "upward pay drift" could be an "unintended consequence" of his wish to limit pay to David Cameron's pound;142,500 salary.
Union experts have also warned that governors might feel compelled to pay the top "PM salary" rate as heads start to view it as a target rather than a limit.
Currently, the top rate is pound;109,500, but governors can offer more cash, on the basis of recruitment and retention or additional responsibilities such as executive headship.
The spotlight fell on highly-paid heads last week, when the GMB, Britain's general trade union, revealed a handful of headteachers earning more than pound;180,000.
Martin Freedman, head of pay at the Association of Teachers and Lecturers, said: "If the pound;142,500 became the statutory maximum, there would be all sorts of pressures for schools to pay salaries approaching that figure. That would have knock-on effects for other members of the leadership groups in those schools and could cause a general upward trend in leadership pay."
However, Emma Knights, chief executive of the National Governors' Association, said she thought pay packets would be unlikely to rise as governing bodies tighten their purse strings in anticipation of the Government's Comprehensive Spending Review this October.
Dr Wright criticised the Education Secretary's plans to bypass the independent pay review body, and fast track the pay cap without the usual consultation procedures, so it can come into effect in September. "I would be concerned about any risk of undermining the integrity of an independent process that has worked well in recent years," she wrote.
Any unilaterally imposed cap on heads' pay, she said, should be an "interim arrangement" pending a full STRB review.
Unions condemn decision to fast-track salary limit
Unions have responded angrily to Michael Gove's request to fast track a pay limit for heads.
In a display of unity unseen for 20 years, leaders of the seven main teacher unions and heads' associations, signed a letter saying by-passing a consultation would "set an unfortunate and potentially dangerous precedent".
Signatories, including the NUT, NASUWT, NAHT, Association of School and College Leaders, Association of Teachers and Lecturers, Voice and Welsh- speaking union UCAC, also criticised Mr Gove's rejection of a School Teachers' Review Body recommendation for the introduction of a list of job criteria for teachers paid as deputy or assistant heads. The letter said his failure to consult was "unprecedented".
A new body, The Education Partnership, will offer unions a sounding board for their views and complaints, but will not give them the same degree of influence.
The unions' anger comes a week after it emerged Mr Gove was to use measures usually reserved to fast-track anti-terror legislation to push through the new Academies Bill.
Fears were raised that the bill would face less scrutiny before becoming law, as it emerged MPs will have only 30 minutes to table amendments after the second reading, rather than the usual days or weeks.
Original headline: Gove warned PM salary cap for heads will increase pay packets