Headteachers could have their salary details revealed publicly, if ministers accept the recommendations of a new report.
The Hutton Review of Fair Pay in the Public Sector, published this week, has recommended that "all organsations delivering public services" disclose the complete paypackets of all executives.
The figures, it said, should be broken down into salary, allowances, performance related pay, employee pension contributions, and the cash value of other benefits.
David Trace, head of the pay and conditions committee at the Association of School and College Leaders, said it would argue to publish only the pay range heads were paid in, rather than the precise amount.
The report, produced by journalist and economist Will Hutton, also asked the Government to ditch "arbitrary benchmarks" for public service pay, such as the prime minister's salary.
The report said: "Pay should reflect their due dessert and be proportional to the weight of their roles and their performance."
The report also discusses the possibility of bringing in performance pay for senior public servants.
NUT general secretary Christine Blower said Hutton was "wrong" on this. "It distorts pay structures, undermining fairness and teamwork by introducing subjective pay decisions that in education would depend on the budgetary position of the school," she said.
Unions have long campaigned for more transparency in heads' pay, especially in the growing number of academies, which are not obliged to stick to the national pay and conditions framework.
Last year, it emerged that a handful of headteachers who were earning over #163;180,000.
The School Teachers' Review Body is due to report its recommendations on creating a clearer pay structure for high-earning heads later this month.