The school effectiveness framework (SEF) is in danger of being used as a cover to disguise "woeful underfunding" of education in Wales, a teaching union has claimed.
Welsh members of the NASUWT used their annual conference in Birmingham to raise serious concerns about the Assembly government's attainment-raising policy, which is set to be rolled out from September.
A motion proposed by executive member Suzanne Nantcurvis, a geography teacher at Ysgol Dinas Bran in Llangollen, Denbighshire, claimed that the ground-breaking strategy could be used as a cost-cutting measure and to reduce the teacher workforce.
The introduction of the framework will be one of the biggest changes to the education system in Wales for decades.
Based on the concept of tri-level working - a partnership between the Assembly government, local authorities and schools - it aims to reduce variations in attainment between schools and even between individual classrooms.
After a successful pilot last year, it will be taken forward from September by four regional groups to meet local educational needs.
Estyn, the Welsh inspectorate, will be a key player in its success, having aligned its common inspection framework, also being launched in September, to fit in with the framework's core aims.
While there has been general support from the teaching profession, there have been suggestions from some quarters that the Assembly government will use the policy as a "sticking plaster" to cure all the ills of the education system.
The NASUWT is the first teaching union to voice such strong concerns publicly.
In her address, Ms Natcurvis said: "SEF has the potential to raise standards and, if used appropriately, could even tackle workload, but the fears are that it will reduce the teacher workforce, increase workload and radically change the nature and structure of the education system in Wales."
She said the SEF could pose a "serious risk" to the structure and nature of the education system, and that it will seek to reduce costs by "ignoring" the importance of the individual teacher.
Rex Phillips, NASUWT's Wales organiser, said the scale of system change will "ring alarm bells" for teachers who will fear the extra bureaucratic burden could overwhelm the education system.
"Frameworks and excessive monitoring regimes do not raise standards or reduce teacher workload," he said. "Wales needs more teachers rather than an increase in the army of observers."
An Assembly government spokesman called the criticism "disappointing" given the level of engagement with heads, teachers and unions during its development.
"This is not a cost-cutting exercise," he said. "Neither is it an additional layer of administration or accountability. It is a commitment to a total system change and defining a new way of working in Wales with stronger collaboration for improved services.
"It emphasises the critical importance of the classroom teacher while putting improved outcomes in learning and well-being for every child, in every learner setting, at the heart of everything that we do."
He said the government had shown its commitment to front-line education delivery with its independent review of education spending, which should be seen alongside the SEF as part of a wider commitment to improve outcomes.
LACK OF CASH PUTS 14-19 PROGRAMME IN JEOPARDY
Teachers have warned that the Assembly government's 14-19 education developments could be "fatally undermined" by a shortage of cash.
Welsh members of the Association of Teachers and Lecturers (ATL) raised the issue at their annual conference in Manchester last week.
They said the extended range of learning opportunities offered by the 14- 19 learning pathways policy was under threat because of a lack of funding.
Schools and colleges are being encouraged to collaborate to offer a wider range of choice for learners. By 2012, all Year 10 pupils will be able to choose their courses from a local curriculum containing a minimum of 30 subject choices.
But ATL Cymru president Gareth Lewis, assistant head of Ysgol Clywedog in Wrexham, said teachers reject the idea that more can be achieved with less money. "We have lots of good ideas in Wales, and teachers welcome Assembly government policies," he said.
"But the fact is, we are being asked to do more and more with less and less. What we should be doing is saying stop; let's examine what's happening to our young people. We are seeing courses oversubscribed and choice being reduced because the money is not there."
Leighton Andrews, the education minister, has said that the annual pound;32.5 million funding the Assembly government provides for the learning pathways policy represents a "considerable investment", and that local networks will determine how their allocation is spent.
Officials hope extra cash can also be found from the ongoing review of education spending.