The trigger for identifying underperforming schools should be an Ofsted judgement of requires improvement and not targets based on exam results, according to an important new commission report.

The NAHT heads’ union Accountability Commission has also called for a major rethink of the way the system works with a focus on giving extra support to schools who need it rather than sanctioning those who miss targets.

The new report, seen by Tes, has warned that the school accountability system in England is failing by driving teachers out of the profession and discouraging them from working where they are most needed.

It also warns that floor targets and an attempt to crack down on “coasting schools” has left “a long shadow of fear for school leaders and teachers.”

NAHT deputy general secretary Nick Brook said that making requires improvement the trigger for more support will ensure that help goes to schools who need while removing the fear of falling below arbitrary targets based on school’s data.

The commission, made up of a range of experts from across the education sector, has urged ministers not to create any new performance targets for schools based on exam or test results.

Instead, it has said that a school being judged to require improvement by Ofsted should be the threshold at which schools receive extra funded support.

Earlier this year, education secretary Damian Hinds announced that he was scrapping both floor targets and the coasting school standards in an attempt to simplify a confusing accountability system and ease the burden on teachers in the face of a mounting recruitment and retention crisis. 

Mr Hinds told the NAHT’s annual conference in May that a consultation would be launched on replacing these two categories with a single measure of school performance.

He said: “We must also have a system that does more than just deal with failure. But we will do so in the right way, and there will be a single, transparent data trigger for schools to be offered support - which we will consult on.”

The education secretary also said it is Ofsted’s job to inspect schools and that he was ending visits to schools by regional school commissioners.

And he told heads that schools would only face forced academisation if it was rated as inadequate by Ofsted. 

This week’s NAHT School Accountability Commission report says that Mr Hinds statements had made it clear that it was Ofsted’s job to determine school effectiveness.

The commission report, Improving School Accountability, said that it makes sense that it should be an Ofsted judgement which is the threshold for deciding when a school is underperforming - rather than data.

Mr Brook said: “The Commission recommends that a requires improvement judgement is the most sensible trigger for additional support.

“It’s a rather obvious solution - if you are found to ‘require improvement’ then you will be able to access additional support to help it happen more quickly.

“By doing so, the government can be more certain that the offer of support to schools is being precisely targeted to those that genuinely need it, rather than simply being triggered by pupil results falling below a notional data threshold.” 

The report has questioned the reliability of Ofsted’s judgements. However, the commission says the inspectorate still has an important role in identifying underperformance but wants it to go further in providing “detailed diagnostic support to schools to ensure they can improve”.

The commission report says: “Ofsted will continue to review the performance data of all schools to determine which schools prioritise for inspection. Significant and ongoing drops in performance will trigger an inspection visit to understand the context and story behind the change in data.”

The report adds: “Inspection could provide schools determined as requiring improvement with a precise diagnosis of areas for improvement, thereby enabling better targeting of relevant support to need. It is important that there is a change in tone for schools within this category - the old clock is ticking mentality is unhelpful to deep sustainable improvement.”