While the top-earning principals have enjoyed rises of up to three times the rate of inflation, managers have seen a real-terms cut in pay. An Association of Colleges’ survey says heads of department pay has remained almost static, with a decrease for assistant principals.

Sue Dutton, the association’s deputy chief executive, said: that there had been a 44 per cent increase in management vacancies, “indicating that many senior managers are now prepared to leave the sector for better rewards in schools, higher education, and private industry.

” If it continues, this trend raises questions about the capacity of the sector to prepare its next generation of leaders.”

Managers were also coming under more strain because of changes, including mergers and increased cooperation with universities and school, which were making their jobs more complex, she said. The AoC has based its calculations on median salaries.

On this basis, head of department salaries have increased by 0.26 per cent in real terms and assistant principals have seen a fall of 0.45 per cent in real terms.

Assistant and vice-principals’ pay increased by 1.95 per cent.

The Association for College Management, many of whose members are covered by the survey, says pay needs to be looked at in the context of the whole college structure.

Nadine Cartner, ACM education officer, said: “Whatever is agreed, all colleges can set whatever levels of pay they like. If you prioritise pay you have to ask yourself what drops out of the equation. Is it support for dyslexic students?

“We need to look at the money coming in in the autumn of 2003 to modernise pay across the board for everybody who works in colleges.”

The survey of 381 colleges in England showed that, excluding emoluments, 10 per cent of principals earned more than pound;94,500.

The average salary for a level 2 deputy or vice-principal is pound;52,500, with the top 10 per cent earning more than pound;64,000, according to the AoC survey.