Headteachers of 53 schools in West Berkshire have written to parents and carers warning of a “funding crisis”.
It was sent out last month, stating that a new national funding formula will mean that tough decisions would need to be taken, and that they could not guarantee that such cuts would not affect teaching.
The headteachers also said they would be raising their concerns with West Berkshire Council and the Government.
The letter said: “With increasing costs placed onto all schools, including higher pension and national insurance contributions, as well as the introduction of the apprenticeship levy, the new formula will not bring the benefits that we had hoped to see for West Berkshire children.
“We will work hard to ensure that cuts have the least impact on teaching possible.
“However, rising costs and a frozen budget mean that tough decisions will have to be taken, and we cannot guarantee that such cuts will not affect teaching, despite doing our utmost to prevent this.”
The new funding formula was unveiled last year as a way of evenly distributing funding out to schools across the country.
Under the formula, West Berkshire would see its funding drop by 0.2 per cent, or £217,654, while some authorities would see their allocation increase by up to eight per cent.
The National Audit Office has estimated that it will see a £3billion cut in real-terms across all schools by 2020.
It is due to come into force from September, however the National Association of Head Teachers (NAHT) has warned that the general election could see its implementation delayed, or even abandoned altogether.
Paul Field, headteacher at Basildon Primary School and the Green party candidate for Newbury in the upcoming election, was one of those who signed the letter.
He said: “For a government to deliberately mislead people with statements about funding being better than it has ever been is outrageous.
“They know that in real terms schools will lose £3bn by 2020 and their dishonesty is an insult to both the electorate and the professionals who serve our communities.”
A Department for Education spokesperson said: “The Government has protected the core schools budget in real terms since 2010, with school funding at its highest level on record at almost £41bn in 2017/18.
“That is set to rise, as pupil numbers rise over the next two years to £42bn by 2019/20.
“We recognise that schools are facing cost pressures, which is why we will continue to provide support to help them use their funding in cost effective ways and make efficiencies.”
Peta Stoddart-Crompton, spokesperson for West Berkshire Council, said: “We fully appreciate the funding pressure falling on schools and have responded to the DfE funding consultation expressing our views about the proposed impact on West Berkshire schools.
“We have made suggestions about how the formula could be changed to deliver a better local outcome and await a response.
“In the meantime we are providing every assistance we can, working with the headteacher associations and the Schools’ Forum to help schools manage within their available resources.”