Britain's biggest headteachers' association has attacked proposals by its rival union which would let people who have not qualified as teachers run schools.
The National Association of Head Teachers is among organisations providing evidence for a review being carried out for the Government which could transform the role of headteachers and their assistants.
The Association of School and College Leaders has recommended that teaching experience should no longer be a prerequisite for becoming a head and that the post's title should be changed to "principal".
Some Department for Education and Skills insiders also back attracting heads from non-teaching backgrounds as a solution to the recruitment crisis.
But the NAHT, which has 39,521 members in primary and secondary schools, will firmly attack the move in a document it is submitting today to the leadership review. It states that the association "does not support the argument that school leaders need not be teachers. A solid base in first-rate practice is required so that heads may properly judge the educational impact of strategic decisions for which they are responsible,"
The submission also questions why people in England who have not qualified as teachers are allowed to take the national professional qualification for headship (NPQH), although this is blocked in Wales.
Chris Howard, head of Lewis school Pengam in Bargoed, south Wales, led the NAHT committee which produced the report. "The Government seems to be trying to do to the education service what it has done to health," he said.
"Bringing in non-doctors to manage hospitals has meant that clinical decisions have been superceded by budgetary ones, and we have seen oncologists complaining that people are not getting the medication they need. A similar approach to schools would also be disastrous."
The NAHT said the difficulty of putting non-teachers in charge was illustrated by the case of an unnamed infants school in the north of England, whose bursar had decided to stop spending money on sand because he did not deem it useful. Its deputy head is reported to have responded:
"I've improvised many things during my teaching career but I'm not improvising sand."
The union's submission also warns that schools are being partnered in federations in some parts of England simply to mask the lack of applicants for headship.
It calls for clearer differences between the pay of heads and senior teachers and for a reduction in bureaucracy, which it says is continuing to worsen despite attempts to give schools greater independence.
"The issue, in a nutshell, is that leadership posts are unnattractive and although new models of school leadership are emerging, they will not, in themselves, resolve the problem," it states.
The leadership review is being carried out for the Government by PricewaterhouseCoopers, which is expected to publish interim findings later this month and a final report in December.
A National College for School Leadership spokeswoman said that a handful of people had gained NPQH without qualified teacher status (QTS). They were either bursars or senior teachers in independent schools, which do not require staff to have QTS.
"Although they do not need QTS, they do have to provide evidence on their application that they have whole-school leadership experience," she said.
The Department for Education and Skills said it was "nonsense" to suggest that schools were federating to cover up headteacher vacancies. "Head vacancies have remained low and stable for some years now," a spokesman said. "Less than 1 per cent of schools at any one time will have a head vacancy and even then there will always be an acting or temporary head in place."
The DfES said that no one had been allowed to run a school without NPQH since 2004, a qualification which required "sufficient school leadership experience".