A senior union leader has called for Ofsted inspectors to be paid more to stop them being “lured” to academy trusts with the promise of better pay and conditions.

Nick Brook, deputy general secretary of the NAHT headteachers’ union, said the outflow of senior staff had left inexperienced inspectors “facing off” against senior ex-inspectors at academy trusts who can “run rings around them”.

Mr Brook, who was a deputy director at Ofsted for almost four years, made his “controversial” proposal at the annual conference of the National Governance Association in Birmingham.

He said that becoming one of Her Majesty’s Inspectors (HMI) was once the pinnacle of a school leader’s career.

“These days, though, the role of the HMI is changing,” he said, “and for many it has just become a stepping stone on the route to far more lucrative jobs at academy trusts.

“Many HMI now serve less than two years at the inspectorate, which barely gives them enough time to get up to speed before leaving.

‘The best Ofsted inspectors are being lured away’

“The simple truth is this, and it’s that Ofsted cannot compete financially with medium or large academy trusts.

“The best HMI are being lured away by offers of considerable more money and less fraught working conditions.”

His comments echoed concerns raised by chief inspector Amanda Spielman about academy trusts poaching her staff, and by her predecessor Sir Michael Wilshaw about the inspectorate being unable to afford the right calibre of inspectors.

And in September, Tes revealed how Ofsted had lost the equivalent of two-thirds of its current HMI workforce in just three years.

Mr Brook had earlier outlined the recommendations of a high-powered commission looking at the school accountability system, which he chaired and which called for Ofsted to have a new role in identifying struggling schools and helping them to improve.

He said: “Now the commission’s vision that Ofsted should provide stronger diagnostic support to schools that are struggling depends upon Ofsted having inspectors with experience, with insight and with clarity.

“If we are going to expect more from HMI, we should be prepared to pay more for HMI. What’s the alternative, really?

“Apart from anything else, I have heard it said that, in some instances, inexperienced inspectors are finding themselves facing off against a panel of former senior HMI in an academy trust who, to put it bluntly, can run rings around them.

“How can that be right?”