Schools are carrying out mock inspections in a bid to prepare for visits from inspectors, according to the National Union of Teachers (NUT).
In some cases these practice sessions are conducted by Ofsted inspectors who “tout” themselves around to schools, the union suggested.
The suggestion comes as the NUT are due to debate a motion at their annual conference, in Liverpool, calling for Ofsted chief inspector Sir Michael Wilshaw to quit and for the inspectorate to be abolished.
Speaking ahead of the conference, NUT general secretary Christine Blower raised concerns that some schools are setting up practice inspections in a bid to prepare for an Ofsted visit.
Many schools are on “constant Ofsted alert,” she said.
In some cases, headteachers can be told of an inspection on Monday, have their schools inspected on Wednesday and “by the next Monday they could be out the door”, Ms Blower suggested.
While classroom teachers may not be in the same situation, she said that after an inspection, some “will be at their GPs saying ‘I can’t take this anymore’”.
Ms Blower said that they did not have evidence that schools were increasingly taking part in practice inspections, but added: “It’s probably increasing in schools who think they are more vulnerable to Ofsted inspection.”
The NUT is urging its members to refuse to co-operate with mock inspections.
NUT deputy general secretary Kevin Courtney said:“We don’t like the practice inspection system because we don’t like the Ofsted inspection system.
“It is highly stressed, not very useful and a top down system. The practice system is just the same, it is completely unnecessary.”