Ofsted will not make allowances for schools that have been forced to cut subjects because of funding pressures, Amanda Spielman has said.

The new inspection framework, which comes into effect in September, puts a schools’ curriculum at the centre of the inspection process.

The new system is being introduced at a time when many schools have reported cutting back some curriculum areas because of budget constraints.

In a Facebook Live interview with Tes at the International Festival of Learning at West Suffolk College today, the chief inspector said the “scope of inspection” did not allow it to take this into account when grading schools.

Ms Spielman said: “Ultimately, the inspection grades have to be justified to a parent. As inspectors, what you cannot do is say, ‘Well, this school would be as good as the other one if it weren’t for X.’

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“You have to give parents an honest view of the quality of education their child could expect if they went to that school.

“Now, it’s absolutely possible to have the conversation - in fact we’re doing a piece of work in this area looking at some schools’ allocation of resources - but unless the scope of inspection changes we won’t be able to report back and say, ‘This school isn’t doing X because of this big a gap in its budget.’”

When it was suggested that her response may worry heads who have had to cut expensive subjects because of budget pressures, she said: “The ways that choices get made and the prioritisation will probably at the very least throw up some extremely interesting conversations about what’s been prioritised and why.”

In the interview, Ms Spielman also played down concerns about the reliability of inspectors looking at curriculum at secondary schools, after Ofsted this week revealed it had put in place extra training.

She also dismissed fears that schools would be under pressure to produce perfect workbooks to impress inspectors.

Answering questions submitted by Tes users, she talked about how more heads of departments would be involved in inspections, talked about whether it was really possible to judge the quality of education in a two-day inspection, and how Ofsted is taking a greater interest in the mental health of teachers.

Ms Spielman also said we should not be worried by a fall in the total proportion of schools that are rated good or outstanding since August 2017.