But they face a lottery depending on where they work, according to the Secondary Heads Association. It says heads in the south-east more likely to get an award than those in the North.

More than 28,000 heads and deputies received extra salary points for performance last year, compared to less than 12,000, or barely a quarter, six years ago.

The average head won a performance bonus of pound;1,000, with some getting as much as pound;1,700. With this year’s 3.7 per cent pay rise, salaries have risen by up to pound;4,000.

The average deputy received a pound;500 pay award, rising to pound;1,000 for some.

The Department for Education and Employment said the awards had been underpinned by pound;70 million in grants to support pay reform.

But the SHA said governing bodies in the shires and the North had found i harder to find the money. More importantly, schools in the affluent south-east have had to bump up pay to hang on to heads.

“There are parts of the world where governors will think pound;50,000 a year is a pretty good whack,” said Chris Nicholls, SHA’s salaries officer and head of Moulsham School in Essex. “In other parts, governors will ask how a head can afford to live on pound;50,000.

“In Essex a good number of heads have taken several points in the past few years, but schools are up against competitive salaries in London.”

The news comes as ministers claim growing numbers of teachers are queuing up to become heads and that the balance between men and women is improving.

Applications for the revamped National Professional Qualification for Headship tripled last year to 3,000, with two-thirds of applicants being women, up six percentage points on the previous year. Women made up 45 per cent of applicants from secondaries, where female heads are hugely outnumbered by men. They accounted for 63 per cent of applicants from primaries.

This year’s enrolment round for the NPQH opened this week.