A secondary school’s teachers have voted to strike over “broken promises” of pay rises.

Staff at John Fisher School were told they would get salary increases if they hit performance targets, but the school can no longer afford them because the money has already been spent.

National Union of Teachers (NUT) said its members this week voted “overwhelmingly” to walk out on Tuesday, March 8, after talks broke down with management.

Headteacher Philip McCullagh called on staff to show “emotional intelligence to understand the school’s financial situation”.

Teachers at the school, which is in Purley but is funded by Sutton Council, were offered pay progression dependant on hitting targets and passing appraisals.

But staff who met the criteria were turned down for rises because of “unplanned, extraordinary costs”.

Some of the money earmarked for teachers’ rises was spent on improvements to the Peaks Hill school’s playing field instead.

Richard McKenzie, the school’s union representative, said: “What we want is the salary which is due to us, which the school budgeted for a year ago.

"The teachers have fulfilled their responsibilities to the full, and the school must do the same.”

Andy Gibbons, Sutton NUT secretary, said: “We are told by the Government that teachers will be rewarded for hard work – but this is the reality.

"We have consistently tried to get the school to pay the teachers the money they were promised.

“We go on strike as a last resort, but our members are determined to get what is their due.

"We will continue to keep the door open for talks, but unless our members in the school are treated fairly the strike action will continue."

But Mr McCullagh said: “Nobody is saying the staff do not deserve pay progression, but at the same time we have to be financially aware going forward.

“I can tell you that 91 per cent of the school budget is spent on salaries alone, and 68 percent of that is on teaching staff.

“It is a tremendously difficult decision to make, but it is for a legitimate reason. We are asking for emotional intelligence to understand the school’s financial situation.”

He added: “The money is not going elsewhere – it is a case of unplanned, extraordinary costs."

The union is planning two further days of industrial action if an agreement cannot be reached with the school.