HEADteacherS are backing a complaint to the parliamentary ombudsman about education authorities inspecting their "own" schools under Office for Standards in Education contracts.
The National Association of Head Teachers says the practice can lead to conflicts of interest, and undermines relationships between schools and authority staff.
The ombudsman has yet to decide whether to look into the complaint - made by a former auditor via his local MP, Nicolas Gibbs (Bognor Regis and Littlehampton).
David Hart, NAHT general secretary, wants the ombudsman to investigate, and also called on OFSTED to look into the matter.
He believes the situation has become intolerable because of the more supportive role the Government now expects education authorities to play with schools which contrasts with the more critical demands of inspection.
He said: "It's bad enough local authorities are using their advisory teams to inspect schools in other areas. That diverts staff from the key job of supporting and advising their own schools. It becomes worse if they have the opportunity to inspect their own schools - it could create a distinct conflict of interest."
A motion on the issue has been submitted to the union's annual conference by its Hampshire branch. But John Clarke, head of Hampshire's inspection and advisory service, said: "We are very careful individual inspectors do not inspect their own work."
Chief inspector Chris Woodhead, said: "The law permits LEAs to tender to inspect their schools and there are safeguards.
"Inspection must be objective and impartial. The more involvement those responsible for inspection have with the school the more difficult that becomes. On balance I think it better if LEAs inspect outside their area."