Funding cuts have left Ofsted unable to afford the calibre of staff who can challenge what is going on in schools, its former chief inspector has said.

Sir Michael Wilshaw, who led the organisation from 2012 to 2016, raised his concerns in a fringe meeting at the Labour Party conference about the future of academies under a Labour government.

He said: “You’ve got to have HMI [inspectors] with a track record of improvement. They should have been headteachers.

“My concern about Ofsted is that because it’s been starved of resources over the last few years, it hasn’t been able to employ the calibre of people who need to go into schools to challenge what’s going on.”

His comments come after figures obtained by Tes showed that the inspectorate had lost the equivalent of 71 per cent of its HMI inspectors in just three years.

Ofsted recruitment ‘is a challenge’

In April, Amanda Spielman, who succeeded Sir Michael as chief inspector, acknowledged that “recruitment is a perennial challenge”.

She told a conference: “We live in a world where our experienced inspectors get hired away from us at an astonishing rate, particularly by MATs that don’t have the constraints that we have on pay.”

A month later, the National Audit Office warned that Ofsted needs to come up with a plan to stop shedding staff, and make sure it has enough people to carry out school inspections.

The meeting came on the day that shadow education secretary Angela Rayner announced that a Labour government would put a stop to schools becoming academies, end the free-schools programme, and bring existing academies into the party’s planned National Education Service.

The conference is due to vote on a motion calling for a Labour government to scrap multi-academy trusts.

Sir Michael told the meeting that “it would be bonkers, a huge mistake, to return schools to local authorities”, and suggested the party should instead concentrate on capacity in the schools system.