Two-fifths of school leaders in England have been forced to cut back on support for children with special educational needs due to a financial crisis “more than a decade in the making”, according to a poll.

Seven out of 10 (71%) leaders say they have cut down on teaching assistants (TAs) in the past year, while 49% have reduced support staff. The crisis could escalate as 81% warn of further cuts in the year ahead.

The Sutton Trust’s findings emerge as the government seeks to overhaul the special needs system, with plans to make mainstream schools more inclusive of pupils with special educational needs and disabilities (Send).

Experts say TAs play a vital role in supporting children with Send in mainstream education, and without them it will be impossible for the government to realise its ambitions.

Pepe Di’Iasio, the general secretary of the Association of School and College Leaders, said: “This research shows the contradiction which exists between the government’s aspirations for the education system and the amount of money that it is prepared to provide to realise those aspirations.

“That contradiction is perhaps most stark in the fact that many schools are having to cut resourcing for Send support at exactly the time the government has launched a programme of major reforms which involve far more expectations on mainstream schools.

“Although the government has made some additional funding available, this is unlikely to be sufficient to support reforms on the scale envisaged or address existing funding shortages.”

The government announced a cash-terms increase of £4.7bn by the end of the spending review period, but this will have to cover an expansion of free school meals and pay rises for teachers.

The survey of 1,105 state school teachers, conducted by the National Foundation for Educational Research on behalf of the Sutton Trust, found Send cuts were particularly acute in primary schools (45% v 25% at secondary level).

Three in 10 secondary school leaders had seen cuts to subject choices in GCSEs and A-levels. Almost half (49%) reported making cuts to IT equipment, 47% to trips and outings, and 32% to sports and other extracurricular activities.

Ahead of a government consultation on the funding model for disadvantaged pupils, 86% of senior leaders said they believed the pupil premium – additional funding for children from low-income families – was not enough.

Despite overall increases in school funding, 43% of senior leaders said they were still having to use pupil premium to plug gaps elsewhere in their budget.

Daniel Kebede, the general secretary of the National Education Union, said: “This is the uncomfortable reality that the government simply will not face up to. Schools are running on empty and are having to make cuts to essentials simply to survive. It is indefensible that government continues to underfund schools. It is impossible for schools to meet the government’s ambitions on Send support.”

Paul Whiteman, the general secretary at NAHT school leaders’ union, said school finances remained in a perilous state. “It is clear that much more investment is still needed to turn this situation around and to ensure schools are fully equipped to deliver on the government’s proposed reforms to the broken special educational needs system,” he said.

Nick Harrison, the Sutton Trust chief executive, said: “Schools are in a financial crisis that’s more than a decade and a half in the making, and we’re seeing the long-term results of those cuts today. With ambitious government reforms on the horizon, now is the time to target measures that will rebalance funding towards the pupils and schools that need it most.”

A Department for Education spokesperson said: “Despite deeply challenging choices about public spending, we have continued to prioritise education by putting record investment into our schools, so every child can achieve and thrive.

“In 2026-27 the core schools budget will total £67bn – an increase of £1.7bn from 2025-26 – with pupil premium funding rising to around £3.2bn and further increases planned over the next three years. This includes significant additional investment to make our Send reforms a reality.”