Ofsted has been given the green light to take a closer look at the work of groups running chains of academies.

In a letter, Education Secretary Nicky Morgan said the inspectorate should be able to publish information about the performance of multi-academy trusts (MATs).

But it must not give an overall “binary” judgment about whether a trust is effective or not.

The move comes after months of wrangling between Ms Morgan’s department and Ofsted chief Sir Michael Wilshaw over whether he should be given extra rights to inspect academy chains.

Sir Michael made repeated calls last year to be given explicit powers to inspect the head offices of academy chains, in the same way that Ofsted can look at local council children’s services.

But Ms Morgan, and her predecessor Michael Gove, had argued that Ofsted does not need to be given additional rights to examine the overall management of these groups.

Setting out new rules for academy trust inspections in her letter today, the education secretary said that the watchdog should continue conducting “batch” inspections of academies that are all run by the same trust.

She goes on to say that she would expect that Ofsted would meet with staff from the MAT shortly after these inspections have taken place.

She said: “They should share and discuss the evidence already gathered and collect and consider further evidence to demonstrate the impact of the MAT’s work with its academies.

“While the focus must remain on the academies that have been inspected, I agree the dialogue should include consideration of achievement and other relevant data for all of the MAT’s academies.

“It should also consider the arrangements the MAT has made for the effective overseeing, challenge and support of individual academies.

“Inspectors would then be able to draw together the range of evidence and make a balanced assessment of the work of the chain with the academies inspected.”

Ms Morgan goes on to say that any findings published by Ofsted must make it clear which schools have been inspected and which have not.

“The published letter should also provide information about the performance of the academies which have not been inspected, so that the wider position across the MAT can be understood,” she says.

The education secretary adds that she is pleased that Sir Michael agrees that a simple “binary judgment of the effectiveness or ineffectiveness of the MAT is inappropriate”.

There will be no formal extension of Ofsted’s inspection powers.

Ofsted has previously attempted to overcome the issue of trust inspections by, where there are concerns about performance, conducting inspections at a number of schools run by the same chain and publishing its findings.

In total, it has issued critical letters to four different academy chains - the Academies Enterprise Trust, School Partnership Trust Academies, Kemnal Academies Trust and the E-ACT Trust - after inspecting some of their schools.

Related stories:

‘I am a supporter of Ofsted - and I want it to inspect my academy chain’ - 28 October 2014

Wilshaw: Ofsted ‘winning argument’ over academy chain inspections - 9 October 2014