Image copyright ASCL Image caption Heads could leave the profession, says Brian Lightman

Plans to freeze senior teachers' pay "arbitrarily discriminate" against school leaders, according to the head teachers' union ASCL.

The School Teachers' Review Body (STRB) has recommended a 1% pay rise for most teachers, in line with public sector pay increases.

But there is no increase at the top levels, so some heads will miss out.

A Conservative spokesman said it was right that the higher paid took "more of the burden of pay restraint".

The ASCL says it wants the decision overturned.

The union says that in real terms teachers' pay has declined by 12% since 2010.

It says that by recommending no pay rise for very senior leaders, the STRB is in effect implementing a "pay freeze".

Under-valued

Although the STRB recommended a salary rise of up to 2% for some classroom teachers in the main pay band, it will be up to individual schools to award this based on their teachers' performance.

It adds that school governors could also decide to spend some of their budget on higher pay for senior leaders.

The report says: "As a consequence of recent reforms, governing bodies have considerable flexibility in setting salaries above the maximum of the relevant head teacher pay group, if merited."

Brian Lightman, general secretary of ASCL, described the "pay freeze" as "ill-conceived", saying: "Although the monetary value is small, the message that it sends is that the contribution that some staff make is not valued.

"As many of them may be nearing retirement, there is a risk they will decide not to continue in the profession, thereby further exacerbating the retention problems in the leadership group."

He said "a cost-of-living increase" was needed by all teachers at every level.

Public sector pay

Teachers received a 1% pay rise last year in line with the two-year pay cap across the public sector, introduced in 2012. The 1% cap is to be extended to 2015-16.

A Conservative spokesman said he agreed with the recommendations from the STRB and the government had reformed pay and conditions to give schools greater freedoms in recruiting and rewarding teachers.

"Our pay reforms provide schools with more control over the management of their budgets and allow them to meet their school and community's needs more effectively," he said.

The Liberal Democrats say they will guarantee public sector pay increases by "at least" the rate of inflation up to 2018 and after that make sure pay bodies award "above inflation increase" in public sector pay.