Education minister Leighton Andrews has ordered an urgent review of the attainment-raising school effectiveness framework (SEF) because he is "not convinced" the flagship education policy is "sufficiently sharp", TES Cymru can reveal.
The admission marks an extraordinary U-turn by Mr Andrews, who only two months ago dismissed as "absolute tosh" the concerns of heads and teachers who claimed the SEF had lost direction.
It is part of a package of measures being considered by the Assembly government after Wales's poor performance in the 2009 Pisa (programme for international student assessment) tests.
Headteachers are also set to be given more powers to deal with underperforming teachers and to "drive change" in their schools.
Speaking at teaching union ASCL Cymru's annual conference last week, Mr Andrews said: "We have already taken steps to sharpen the SEF with a clear focus on literacy, numeracy and breaking the link between poverty and attainment.
"But I'm not convinced the SEF is sufficiently sharp. I want to sharpen SEF to give it renewed clarity. I will say more about this in February."
David Reynolds, professor of education at the University of Plymouth, said the SEF was "vital" for Wales's future educational success.
"It is an intervention that will run Wales-wide and includes a number of useful components such as professional learning communities and better provision of data," he said.
"The challenge is to make sure all the pieces of the SEF cohere and support each other. We are in such a difficult situation. We have got to look at the best practice and the best research available internationally, not just within our own system."
Mr Andrews announced that professional learning communities, one of the key components of the SEF, will be rolled out across the whole education system next March. Their aim is to develop teams of systems leaders to challenge schools and promote best practice.
He also said the development of school leaders will be closely linked with the principles of the SEF, and that the new National Professional Qualification for Headship will draw on the knowledge of experienced headteachers.
Mr Andrews told heads that their role had never been more important. "I won't tolerate classroom complacency and I'm sure you won't either," he said.
"It's very clear that you people are in the strongest position to turn things around in schools. I want to see heads empowered and driving change. If there are specific things you want me to look at, I want to hear about them - and fast."
Mr Andrews revealed that his department is to review current performance management of heads and teachers, and to look "with some rigour" at initial teacher training and staff development issues.
Gareth Jones, secretary of ASCL Cymru, welcomed the announcements on performance management and the SEF, but said teachers should not be overlooked.
But Rex Phillips, NASUWT Wales organiser, claimed increased pressure on school leaders could lead to classroom bullying.
"I think teachers do a great job," he said. "You are not going to raise standards or motivate the workforce by putting pressure on them.
"The minister should be very careful of using Pisa as an indictment of the system and should choose his words more carefully. I don't think anyone blames teachers for these problems."
- Original headline: SEF overhaul after drubbing in international league tables