Nearly a third of school leaders made cuts to balance their budget in the last academic year, a survey suggests.

The Government’s “failure to invest” in schools has led to staff cuts, fewer enrichment activities such as school trips, and less support for children who need it, according to school leaders’ union NAHT.

A poll by the NAHT of more than 1,500 school leaders in England in June found that 31% reported making cuts to balance their budget in 2020/21.

More than one in three (35%) believe they will be forced to make cuts this academic year and more than one in four (26%) predict a deficit budget in 2021/22 based on current funding levels.

Heads also raised concerns about the insufficiency of funding for pupils with special educational needs and disabilities (Send) as they said providing required support for these pupils had led to budget pressures.

Nearly all school leaders surveyed said funding for pupils with Send in their school is insufficient, while 79% said they had to fund the purchase of additional services because they were not available or accessible from health and social care, according to the survey.

More than four in five (87%) school leaders said they do not believe that the Covid-19 “recovery funding” they have received to date is sufficient to meet the needs of their pupils.

School leaders will speak directly to MPs on Wednesday at a parliamentary briefing organised by the NAHT.

Helen Spearing, headteacher of a primary school in Staffordshire, said: “We have to restrict the number of school trips because we can’t afford to subsidise them if parents can’t afford to contribute.

“More and more children have complex needs which require additional support but we don’t have the finances to provide extra staff.”

Lesley Roberts, headteacher of a primary school in Berkshire, said: “Special needs is beyond crisis in schools, it’s sucking the money from budgets.”

She said: “We also can’t afford a caretaker or Sendco (special educational needs and disabilities coordinator). As a headteacher in the last two years I have been a Sendco, school business manager, caretaker and headteacher as well as cover for the office and class.”

Paul Whiteman, general secretary of the NAHT, said: “The Government’s failure to invest in schools over the past decade is forcing them to cut back on staff, support for pupils, and activities that enrich the school day.

“Despite all the rhetoric on additional investment in schools, it is clear that school budgets remain under enormous pressure.

“A far more ambitious programme of investment is required from the Government if schools are going to be able to deliver the education that the current generation of pupils need and deserve.”

Kate Green, Labour’s shadow education secretary, said: “Conservative cuts have hammered school budgets during the last decade, delivering the biggest budget cut in 40 years.

“This is forcing schools to cut back the support and the enriching extracurricular activities available to pupils, damaging life chances and holding children back.

“This is being exacerbated by the Government’s paltry catch-up support, with tutoring reaching just 2% of pupils last year.”

A Department for Education spokesman said: “This Government is providing the biggest uplift to school funding in a decade – £14 billion in total over the three years to 2022-23. This is a £7.1 billion increase in funding for schools compared to 2019-20 funding levels.

“Next year, funding is increasing by 3.2% overall, and by 9.6% in 2022-23 for high needs.

“The National Funding Formula continues to distribute this fairly, based on the needs of schools and their pupil cohorts.”