If a governing body has to agree performance criteria with the head, then he or she effectively has an "armlock" on the governors, NAGM says.
Jointly-agreed performance criteria were suggested by the teachers' pay review body after complaints that heads were exploiting the merit pay procedures. Teacher unions alleged heads had "top sliced" school budgets last year by Pounds 12 million in extra pay while few teachers receive performance pay.
At present governors are required to consider whether heads and deputies have shown "sustained overall performance which appreciably exceeds that normally expected" when reviewing salaries. But locally agreed performance criteria, effectively determined by the head, would be just as poor a check on unjustifiable salary increases, NAGM argues.