A major new commission has called for an overhaul of the high-stakes accountability system facing English schools.

The NAHT Accountability Commission’s new report has warned that the current system of Ofsted inspection, league tables and targets is failing by driving teachers out of the profession, discouraging teachers from working in deprived communities and encouraging selfish behaviour from school leaders.

It is calling for an end to targets based on exam results, a scaled-back role for Ofsted and for school leaders to play a more active role in driving school improvement.

Here are its nine recommendations for improving the system.

1. School performance should only be measured against similar schools.

The commission warns that schools should not be judged on the performance of pupils in one year and should not be compared with other schools in different contexts.

It says that comparative performance data which measures school performance against groups of similar across an average of three years is the most reliable performance indicator and should be used by Ofsted when judging school’s effectiveness.

The report says using comparative schools data would level the playing field.

2. Requires Improvement should replace floor and coasting standards

Education Secretary Damian Hinds announced earlier this year that he was scrapping both floor targets and the coasting school standard as the school accountability system had become too confusing.

He told school leaders at the NAHT annual conference earlier this year that the DfE would consult on a single measure to replace them.

Now the NAHT’s accountability commission has urged Ministers not to create any new performance targets based on data but to use an Ofsted judgement of requires improvement as the threshold for deciding when an underperforming school needs more support. It also wants the Government “to change the narrative” with a focus on supporting schools rather than sanctioning them.

3. Ofsted should focus on identifying failing schools and providing a detailed diagnosis on how they can improve

The commission has called for Ofsted’s work to be refocused on identifying school failure and providing more support to help them improve.

It suggests that Ofsted should also continue to have a role in supporting the ambition that all schools are good schools.

It adds: “It should do this by checking that no school is failing or at risk of decline; checking that standards aren’t slipping, investigating the extent to which the school is outward looking and collaborative and rooting out sharp practices and gaming including off rolling.”

4. End the exemption on outstanding schools being reinspected.

The commission has added its voice to calls for no schools to be exempt from inspection.

Since 2011, schools that are rated as outstanding have been exempt from routine inspection from Ofsted.

As the National Audit Office report earlier this year into Ofsted highlighted this has meant that, as of August last year 1,620 schools had not been inspected for six years or more, including 296 schools that had not been inspected for 10 years or more.

Nick Brook, the deputy general secretary of the NAHT who has chaired the commission, has warned that this situation is unsustainable.

The commission has recommended that this exemption is ended - something that Ofsted has called for itself in talks with the DfE.

5. The Ofsted outstanding judgement should be replaced with a new way of promoting excellence

The commission has called for the outstanding category in Ofsted inspections to be abolished and a new way of sharing excellence in the school system be created.

And it does not believe it should be the job of Ofsted to do this. The report says: “The Commission believes that identification of excellence should be firmly anchored within school improvement rather than used as a measure of accountability.”

It calls for a more robust system for identifying specific excellence within the sector, to increase take-up of highly effective, evidence-based practice. It says this should be specific about what a school is doing well and the context in which it is working.

6. Ofsted should commission research on how to make sure its inspections are reliable.

One of the most damning conclusions of the commission’s report is that Ofsted’s judgements cannot be relied upon.

The report calls for the inspectorate to focus mainly on identifying underperformance and giving better diagnostic support to schools to improve.

However, the commission says work is needed to ensure that inspection judgements are reliable. It calls on Ofsted to commission research “to determine the format and nature of inspection required” in order to provide reliable judgements and benefits for schools.

7. Develop a national programme of peer reviews

The commission says that many of the highest performing education systems across the world are moving to “lateral accountability” where schools support and challenge each one another.

The report suggests developing peer reviews of schools would help to “push beyond the limits of top-down accountability.

It has called for existing peer review programmes in schools to be evaluated to establish what works in order to then develop a national accreditation programme of peer review.

8. Develop alternative national standards for headteachers and chartered headteacher status

The commission warns that the government’s current national standards of excellence for head teachers have little impact in the work of school leaders.  It warns that they have not resonated with the profession because they do not “paint a picture of successful leadership recognisable to many highly effective head teachers.”

It said that these alternative standards could show to headteachers the importance of taking ownership of school and system improvement and could help to attract leaders of the future.

The commission also suggests the introduction of chartered headteacher status “giving recognition to their high professional status.”

9. More support programmes for new and aspiring school leaders.

The commission warns that too little attention is placed on the needs of leaders who are new to leadership. The report says that “all too often a sink or swim mentality takes hold, and too many potentially great future leaders sink without the right support and advice.

It recommends that the DfE should develop a programme for deputies aspiring to headship and also a new heads’ programme to help them develop “the skills, knowledge and resilience that new leaders require to improve career longevity.”

It also suggests developing supportive national and local mentoring networks for school leaders; developing an annual event that brings together all new heads and establishing a national network of mentors and coaches. It suggests these steps could reverse the “worrying trends in head teacher attrition”.