Primary headships are becoming increasingly unattractive to deputies who may only receive a small salary increase for taking on a significantly greater workload. Whereas secondary heads are often paid Pounds 10,000 more than their deputies, the differential in primary schools is usually closer to Pounds 2,500 and in some cases may be even lower.

Mark Durbin, deputy of Glasllwch Primary School in Newport, Gwent, has been looking at headships in South Wales for the past few months. In most cases the salary on offer was less than Pounds 1,500 more than he receives as a teaching deputy. “When I assessed the extra travel costs of commuting to Cardiff, I would have been left with less money than I have now.”

Mr Durbin, who currently earns just over Pounds 27,000, has been a deputy head for seven years. At 36 he is keen to seek promotion, yet he is reluctant to swap the pleasant atmosphere at Glasllwch School, a group 2 primary with 226 pupils, for the stress of a headship.

At one Cardiff primary which was advertising a vacancy, the incoming head faced the prospect of making two teachers redundant, cutting the special needs budget and surviving an Office for Standards in Education inspection. “For Pounds 1,500 more, it’s not really a very inviting package,” said Mr Durbin.

According to the Teacher Training Agency, the small differential between many primary heads and their deputies is a major barrier to recruitment - particularly in small primaries. “Smaller schools are readvertising headships far more frequently than larger schools,” said John Howson, former deputy head of Oxford Brookes University’s school of education, who joined the TTA in September.

A primary head in a group 2 school with up to 300 pupils can expect to earn about Pounds 28,000 or Pounds 29,000 for being on points 10-13 of the heads and deputies pay spine, he said. The deputy of the same school would probably earn between Pounds 25,700 and Pounds 26,500 for being on points 4-6.

Mr Howson, who is the agency’s chief professional adviser on teacher supply, said it was not difficult to work out why the headships in such schools were sometimes unattractive, especially to internal candidates. “The head’s responsibilities have grown considerably with local management of schools and OFSTED inspections. The buck stops with the head, not the deputy.”

A survey carried out by Mr Howson last year while he was still at Oxford Brookes found just over half of group 1 schools and 40 per cent of group 2 schools received 10 or fewer applications when they advertised for a head. Some small primaries received just one application.

The problem of attracting a head was especially acute, he added, in very small schools with just a handful of teachers and no deputy. Often these are offering to pay a head’s salary of less than Pounds 26,000.

The deputy of a larger primary who applied for such a post in order to gain “promotion” might easily end up earning less than in their current post. “Either you take somebody without any deputy experience who is a classroom teacher in a small school, or you ask an experienced deputy to take a pay cut,” said Mr Howson.

Earlier this year the School Teachers’ Review Body report noted how the number of applications to fill leadership positions was declining, but it did not make any specific reference to pay differentials.

Stephen Hillier, head of corporate management at the Teacher Training Agency, said the agency had highlighted the issue in its recent evidence to the STRB after prospective primary heads had claimed pay differentials were not sufficiently attractive. “People are becoming less confident about putting themselves forward. Pay is inevitably a factor.”

The National Association of Head Teachers recommends primary and secondary schools to preserve differentials in line with recommendations made on its behalf by Hay management consultants. These take into account salaries earned by managers in commerce and industry.

According to Hay, the deputy of the smallest (group 1) primary should earn no more than 85 per cent of the head’s salary. In group 2 schools the deputy’s salary should not exceed 84 per cent and, in larger (group 3) schools, 80 per cent. Kerry George, the NAHT’s senior assistant secretary for salaries, said actual differentials were much smaller than this in many primary schools.

The NAHT, which used to argue for fixed differentials, accepts this is no longer a serious option as both heads and deputies are subject to annual pay reviews, possibly based on performance. But the union is disappointed that the STRB has declined to carry out job evaluations to compare the work of heads and deputies. Similar comparisons have been used by the Review Body on Senior Salaries to evaluate pay in the armed forces.

In its recent pay evidence, the NAHT accepted that governing bodies often lack the experience and money to raise salaries to make posts more attractive. Schools, it says, nearly always try to save money by appointing a new head at a lower spine point than his or her predecessor.

“It all stems from the starting salary. After that it’s at the discretion of governors,” said Ms George. “We are looking for some way of getting a base starting salary which means people are appropriately valued from the moment they accept the post.”

Mark Durbin, meanwhile, refutes any suggestion that he is being greedy for expecting more money in his first head’s post. “You don’t look for a headship just because you want more money, but you must consider your family. The professional deputy is becoming more and more of a reality because the incentives for moving on are not there.”