Three-quarters of headteachers say that Government plans for all schools to become part of a multi-academy trust (MAT) will not lead to better outcomes for pupils, new polling has revealed.

In the Schools White Paper, published in March, Education Secretary Nadhim Zahawi set out plans for all schools to either have become academies by 2030, or be in the process of joining an MAT by this date.

The NEU teachers’ union has criticised the evidence for the proposals as “badly flawed”.

On Saturday at its annual conference in Telford, survey data by the NAHT school leaders’ union of more than 1,000 headteachers showed that 76% of respondents either disagreed or strongly disagreed that plans for a fully trust-led system would lead to an improvement in outcomes for pupils.

The data also showed a lack of appetite among school leaders for joining academy trusts. Less than a fifth – 17% – of those not already in an MAT said they expected to join one within the next four years, while 62% said they did not expect their school would choose to join an MAT at any point in the future.

For those whose schools were already part of a trust, nearly six in 10 – 57% – said they were very satisfied or satisfied with the experience, citing the increased collaboration between teachers and leaders across MATs, centralised finances and human resources, and greater access to shared teaching materials as benefits of being part of a trust.

Paul Whiteman, NAHT general secretary, said: “NAHT is proud to represent leaders in all different types of schools, including those in Local Authority Maintained Schools, standalone academies, as well as those in multi-academy trusts.

“We know that excellent teaching and learning takes place in a wide range of different contexts, and ultimately it is people, not structures, that makes the biggest difference to pupil outcomes.

“We also know that many leaders already working in multi-academy trusts have found benefits in doing so,” he said.

“However, this new data shows that the Government has a lot more work to do if it is to convince all school leaders that its plans for for further structural reform will have a positive impact on pupil outcomes.

“School leaders not currently in an MAT have told us that they can see some potential advantages to being part of a trust, but they also have a number of important and legitimate concerns that the Government will need to properly address if it is to make progress on the goal it has set itself in the recent White Paper.”

Heads cited concerns such as a loss of autonomy as a school leader (92%) or a loss of autonomy for the governing body or trust board (74%) when asked about why they might not want to join an MAT.

They were also worried about retaining the unique local context of their school (83%), and concerned about the financial impact on the school (60%).

School leaders said they would be more likely to join an MAT if they had greater rights to leave a trust when it was not working for their school, as well as greater protections around funding to prevent pooling of funds by the trust.

Mr Whiteman said: “There are legitimate concerns about autonomy that the Government needs to consider if it wants to convince school leaders and governing bodies of the benefits of joining MATs.

“The concerns raised about retaining a school’s local context and funding arrangements are ones that are reflected by parents and schools’ local communities as well.

“Before we move any further to a fully MAT-led system, it is vital that proper consideration is given to how schools can ‘divorce’ their MAT when things aren’t working, as well as to what interventions will be made when MATs under perform.”

A Department for Education spokesperson said:“We want all schools to be part of a strong academy trust so they can benefit from the trust’s support in everything from teacher training, curriculum, financial planning and inclusivity towards children with additional needs, to excellent behaviour and attendance cultures.

“The NAHT’s own findings show most school leaders already part of a trust are benefiting from this support, helping them focus on what parents and children want and need – great teaching for every child.

“We will be working with the sector and unions over the coming months and years, as we move towards a fully trust-led school system, to improve how trusts are regulated and held accountable for their work to support their schools and communities.”