Teachers' unions have reacted angrily to reports that some heads are to receive pay rises of up to 9%, while classroom teachers will get less than half that.

The BBC's Mike Baker reports on the unions' anger

It is understood the government has accepted the recommendations of the pay review body over the issue of primary school heads.

The pay review body appears to have responded to evidence submitted by the National Association of Head Teachers which stressed the difficulties many primary schools are having appointing heads.

It called for a big pay award to bring head teachers in line with comparable management jobs in industry.

The pay deal is expected to give primary school heads between 6% and 9%.

The increase will depend on the size of the school, with the biggest going to the smallest schools, where most heads earn around £30,000.

Heads in secondary schools will also get larger than average rises, between 4% and 6%.

The overall pay rise is expected to range between 3% and 4%, beating the rate of inflation - and presenting some education authorities with a dilemma.

They say extra government funding this year will cover an overall increase of no more than 3% and any bigger increase, without extra cash to fund it, could put pressure on teachers' jobs and other government priorities like smaller class sizes.

Teachers angry over pay reports

The much lower pay award for classroom teachers has angered other teaching unions which are still smarting after last year's pay award was phased by the government.

Nigel de Gruchy of the NASUWT said this was "appalling treatment for the poor infantry in the classroom."

Doug McAvoy of the National Union of Teachers said addressing one part of the problem would not deal with the bigger problem - namely the fundamental crisis in teacher recruitment.

This pay award is the last before the introduction of the government's controversial plans for performance-related pay for teachers.

One union leader said this differential award could sour negotiations over these plane.

The pay settlement, due to be announced on Monday afternoon.