Of the 11,000 schools that responded to the NAHT study, 66% said they would have to make teaching assistants redundant or reduce their hours.

Half said they were looking into making teachers redundant or cutting their hours.

The NAHT said schools were struggling to cope with rising costs including energy bills.

Paul Whiteman, NAHT general secretary, said: “Schools are being hit by a perfect storm of costs.

“In attempting to balance their budgets, school leaders are being faced with eye-watering energy bills, spiralling costs to resources and supplies, and the financial impact of an unfunded pay increase this year.”

“With no fat left to cut following a decade of austerity, many thousands of schools are now looking at falling into deficit unless they make swingeing cuts. Education is truly in a perilous state.”

95% of schools say they will be in deficit next year

More than half (54%) of schools in England said they will go into deficit this year, unless they make further cuts.

Just 5% of those asked said they would be able to pay their costs for the 2023-24 academic year without going into debt.

Most schools are not allowed to be in a deficit, and are therefore now looking at ways to cut costs to balance the books and prevent this happening.

Cuts to non-education support

After cutting teaching staff or hours, respondents listed other areas where they would need to make cuts.

Of those asked, 58% said they would reduce investment in equipment for schools, 56% would cut back on maintenance spending, 54% would cut back on CPD investment including teacher training days, and 51% would cut back on energy consumption.

Non-educational support services such as counselling therapy and mental health support would be cut back by 47% of schools.

While 44% said they would have to reduce spending on additional targeted interventions for pupils requiring additional support.

A third (31%) said they will have to reduce the number of children receiving tutoring support through the National Tutoring Programme (NTP).

The NAHT says school funding is due to be 3% less in real terms in the year 2024/25 than it was 15 years before in 2010, according to data from the Institute of Fiscal Studies (IFS).

It says this equates to a nearly £2bn shortfall, equivalent to £40k for the average primary school or the pay of one teacher, and £210,000 for the average secondary school, or the pay of four teachers.

‘Schools have no option but to make redundancies’

The NAHT is now calling on the government to address education spending ahead of next week’s Autumn Statement.

Mr Whiteman continued: “After a decade of austerity, schools have made all the easy savings already.

“The only things left to cut are things that will have a real immediate impact on children – and especially those who are already the most disadvantaged and vulnerable. This goes against everything school leaders strive for, and the anger and desperation I am hearing from my members is unprecedented.

“The responses to this survey represent a significant proportion of the education profession – leaders out there in schools, on the front line, who are seeing the true desperation of the situation at hand. They do not raise the alarm lightly – when they speak, the government must listen.

“We must see urgent action on education spending ahead of the next Budget update.”

A Department for Education spokesperson said: “We understand the challenges facing schools driven by high inflation. To support them at this time, we are providing schools with £53.8 billion this year in core funding, including a cash increase of £4 billion for this financial year. This is a 7% per pupil increase in cash terms across schools and high needs.

“All schools will benefit from the Energy Bill Relief Scheme, reducing how much they need to spend on their energy and giving them greater certainty over their budgets over the winter months. We are also providing schools with tools and information to help get the best value for money from their resources.”