The head of Ofsted has accused the “most vocal critics” of the proposed reforms to revamp the grading system for schools of misunderstanding that a “low-accountability system” was possible.

Sir Martyn Oliver, chief inspector of Ofsted, said proposed report cards for schools are “not and never were going to bring about the end of grading”.

In a speech to the Association of School and College Leaders’ (ASCL) annual conference in Liverpool, Sir Martyn said giving parents and families the information they need in a clear and accessible way was a “must-have”.

Addressing around 1,000 school and college leaders on Friday, the chief inspector said report cards were never “going to be about less accountability”.

Headteachers in the audience at the conference laughed when Sir Martyn said he did not want them “to be doing anything ‘for Ofsted’”.

Last month, Ofsted launched a consultation on its plans to introduce a new report card system for grading schools in England.

Schools in England could be graded across a variety of different areas – including attendance and inclusion – using a colour-coded five-point scale.

They would receive ratings – from the red-coloured “causing concern” to orange-coloured “attention needed”, through the green shades of “secure”, “strong” and “exemplary” – for each area of practice under proposals for Ofsted’s new report card system.

Education unions have criticised the proposals for being even worse than the system they would replace.

Addressing some of the criticism, Sir Martyn said some responses were “seemingly built on a misunderstanding of what report cards are”.

He told the ASCL’s conference: “Report cards are not and never were going to bring about the end of grading.

“They are not and never were going to sacrifice much needed clarity for parents.

“And they are not and never were going to be about less accountability.”

He added: “Anyone who thought that report cards were going to end assessment was mistaken.

“And they weren’t paying close enough attention to what parents want, what politicians promised, and what children deserve.

“They only get one childhood, one chance. Making sure we are getting it right, and striving for better every day, is not just important, it is absolutely vital.

“I’m sorry if that’s blunt. But I don’t believe in dodging the difficult.”

In his speech to school and college leaders, the Ofsted chief said: “But the most vocal critics of the proposed reforms seem to be under the misapprehension that a new low-accountability system is possible. It isn’t.

“Of course, our top priority has to be giving parents and families the information they need in a clear and accessible way. That’s not a nice-to-have for them, it’s a must-have.”

Ofsted has faced criticism following the death of headteacher Ruth Perry.

Mrs Perry took her own life in January 2023 after an Ofsted report downgraded her Caversham Primary School in Reading from the highest to the lowest overall effectiveness rating over safeguarding concerns.

A coroner concluded the Ofsted inspection in November 2022 had contributed to Mrs Perry’s death.

The Government announced last year that headline Ofsted grades for overall effectiveness for schools in England would be scrapped.

Previously, Ofsted awarded one of four single-phrase inspection judgments: outstanding, good, requires improvement and inadequate.

Ofsted has rolled out a series of changes to improve its inspection process.

During his speech on Friday to the conference, Manny Botwe, president of the ASCL and headteacher of Tytherington School in Macclesfield, said the planned changes for the new report card system felt like “a kick in the teeth”.

He called on the Government and Ofsted to “rethink” their consultation proposals for inspections.

He said: “More high-stakes accountability is not the answer.

“We need a system that is genuinely supportive, a framework that helps schools and colleges improve rather than simply judging them.

“Inspection must be about collaboration and support, not fear and punishment.”

Addressing the proposed accountability reforms in her speech to school and college leaders on Friday, Education Secretary Bridget Phillipson said: “I know the proposed changes are challenging.

“I know they spark debate, but that’s right where education should be – at the heart of our national conversation.

“That’s why we’re consulting on this, why Ofsted are consulting on their proposals to improve inspection. They are genuine consultations.”