New standards to be set for assessing teachers will be drawn up in consultation with the profession, Helen Liddell pledged.
"We recognise that this raises important issues. How is excellence defined and assessed? How are equality of opportunity and fair treatment ensured? How are financial and non-financial rewards balanced?
"Measuring performance accurately and confidently must be an essential underpinning of any scheme to reward good teaching. And this will not be simple or straightforward. I am under no illusions about that."