To assume that only one-third of experienced teachers are worthy of merit pay is an insult. And former education secretary Estelle Morris expected heads to use their judgment and local knowledge to determine the extent of staff effectiveness.

To realise now the consequences of the projected impact on the national budget is unforgivable.

Before his appointment as head of the standards and effectiveness unit, Michael Barber wrote The learning game, arguments for an education revolution. In it, he says that “the research into merit pay is mixed and it appears to work only where three conditions have been met:

* where teachers are well paid and the merit pay is an extra;

* where there are published criteria on the level of performance required to gain the merit pay;

* where everyone who meets the criteria receives the pay.”

He adds: “These conditions do not exist in British schools.”

Yes, he was writing at the end of the previous government’s tenure, but it would seem we are about to head backwards I suggest that current Education Secretary Charles Clarke reads Barber’s book and thinks again about the profession that he depends upon to deliver the standards he argues for.

David Porritt. Headteacher. Bethany CE VA junior school. Knole Road, Bournemouth