The promised review of the pay system for head and deputies is likely to extend beyond studying recruitment and the assessment of performance.
After admitting that the present system is not working well, the teachers' pay review body is under pressure to come up with an alternative way of determining how difficult it is to lead a particular school, placing less emphasis on the age of pupils and the numbers on roll.
Salaries for heads and deputies are currently based on a 51-point spine ranging from around pound;25,000 to more than pound;57,000 per year. The minimum salary payable to a head or deputy is determined by a school' s group size , though governors can exercise their discretion whether to pay more.
A consultative document expected to be published by the review body next month will ask whether the six groups and the points they relate to on the spine are appropriate. It will also reconsider the pupil-weighting system which determines a school's group size.
Among the questions it may examine is why the head of a 13 to 18 secondary school receives a higher salary than the head of an eight to 13 middle school with exactly the same number of pupils. And why should primary heads who combine management tasks with a teaching timetable earn substantially less than secondary colleagues?
The National Association of Head Teachers wants more emphasis to be placed on a head's workload. "The group sizes and their range on the spine don't reflect what heads actually do," said Kerry George, the NAHT's senior assistant secretary for salaries.
John Howson, an analyst of teacher supply, agreed the review body was going to have to look at an "antiquated" system developed after World War II when most heads were teachers more than managers. "The head of a group 5 secondary school has a number of secretaries and deputies," he said. "The head of a group 1 primary with 150 pupils will only have a certain amount of non-teaching time. If something crops up during that time, he or she has to take the work home."
Together with the Secondary Heads Association, the NAHT has proposed changes which would increase the value attached to primary children and pupils aged 11-16 at the expense of sixth-formers.
Kath Brooke, SHA's salaries officer, said such a change would benefit all primary heads and heads of secondary schools without sixth forms. SHA also believes the groups which determine a head or deputy's starting point are too large and that two or three sub-groups should be created within each of the present groups.
Just over half of the 21,000 primary heads in England and Wales are in school group 2 which means they earn between pound;28,281 and pound;34,383. No primary school is large enough to be in group 5 or 6.
The 4,300 secondary heads are spread across all group sizes but the largest number (1,800) are in group 5 and earn between pound;39,657 and pound;50,610.
Unlike class teachers, heads and deputies do not automatically move up the pay spine each year. SHA will propose that new heads and deputies should receive a mandatory increase in spine points for three years in recognition of the extra experience they are gaining.
Governors currently have discretion whether to move an individual up the spine based on recruitment and retention factors, responsibilities of the post and performance. Mandatory increases in spine points are unlikely to find favour with the STRB which, two years ago, said that any upward movement should follow a performance review.
The new consultative document will go further by asking whether part of a head's salary should be directly linked to school improvement targets due to come into effect in September. But there is little indication so far that governors are keen to look at performance criteria.
According to Kerry George, the current performance reviews are meaningless because governors do not have enough money to raise salaries even when a headteacher or deputy has done well. "We must have a system which sets down what people can achieve and rewards them rather than raises expectations that cannot be realised."
Both the NAHT and SHA have reacted coolly to a suggestion made last year by local authority employers that schools should base heads' pay on local salary bands. These would be drawn up by LEAs according to local market conditions.
Each band might cover up to eight spine points with schools experiencing recruitment difficulties more likely to offer a salary at the top end. Mike Walker, spokesman for the LEA employers organisation NEOST, said local salary bands might encourage schools to vary heads' pay more than at present. "Governors are told they have flexibility but don't know how to use it," he said.
Pat Petch, chairman of the National Governors' Council, said governing bodies would need convincing of the value of local salary bands. The NGC believed there was already sufficient flexibility - even if there was rarely enough money.
"The bottom line is often between paying more money to a certain member of staff or preserving the jobs of others," she said. "If it's a choice between jobs and pay, then jobs have got to win." In spite of widespread fears over a shortage of primary heads, this year's review body report noted how secondary schools are finding it slightly more difficult to fill headships than primaries. Unfilled vacancy rates remain below 1 per cent in both sectors.
According to John Howson, many governing bodies already reflect market conditions by initially advertising a headship at one salary and then increasing their offer if forced to readvertise. The problems, he said, are the narrow pay differentials between heads, deputies and other primary staff.
These could become even smaller if teachers are able to earn extra money by taking on new duties, such as running homework clubs at pound;9.70 per hour. "Unless you add another pound;5,000 on to primary headships they are starting to look deeply unattractive," he said.