She and the Government are obsessed with the notion of "something for something" without ever recognising how much they had for so little. She now says "pay progression should be linked to greater challenge for the individual on the basis that increased public spending should purchase a more effective contribution from each member of the workforce".
This phrase contains the extraordinary assumption that teachers have a reserve of quality work which they have hitherto held back until they can sell it for the Chancellor's extra money; an assumption so out of touch with reality as to be incredible. There is no evidence that PRP helps motivate, recruit and retain teachers.
I could list a range of studies which confirm teachers' opposition to PRP. A study for the National Union of Teachers carried out by Warwick University's institute of education and a separate study by Exeter University stand out, but it is worth looking at a further two.
Ray Richardson's 1999 study of PRP in other public services confirmed that it led to division and jealousy among staff. Three years on, Maurice Galton's and John MacBeath's study of primary teachers confirmed teachers' views that performance management had a negative impact on pupils' opportunities as well as on their own working conditions.
So how has the current PRP scheme been handled by headteachers? The answer is, by acting to protect their staff from invidious distinctions about performance. Well over 90 per cent of teachers passed the threshold in rounds one and two. Also, both the National Association of Head Teachers and Secondary Heads Association, following the NUT's lead, have advised their headteacher members that they need only confirm that their post-threshold teachers have maintained their threshold standards to move to the next point; advice which contradicts the Government's approach.
Heads have done this because they do not want to undermine a culture based on teamwork; the best culture for raising standards. Heads know that they are more likely to achieve high standards with staff prepared to co-operate with each other than with staff riven by infighting over ownership of good ideas and results. The vast majority of teachers are working effectively and cannot work harder.
This is a culture the Secretary of State fails to comprehend and seeks to break. She believes that the "carrot and stick" approach applied to individual teachers is a far better incentive to raising standards than encouraging teachers to work together.
However, for the small percentage of teachers who failed to cross the threshold, the effect has been devastating. Many have left the profession. Others have remained but are thoroughly demoralised. Does she want to visit that effect on teachers in their early years in the profession when the drop-out rate is already 50 per cent?
Instead of continuing to dig, Estelle Morris should conclude that by all the evidence available, PRP has failed. She should sit down with teacher organisations and employers to agree a pay structure which enhances standards and supports teachers.
Doug McAvoy is general secretary of the National Union of Teachers