Almost two dozen schools in Oxfordshire ran at a deficit in the last academic year, new figures reveal.

It comes as the number of schools losing money across England soared last year.

The Association of School and College leaders said government investment has "failed to keep pace with rising costs", warning deficits will harm pupils' education.

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Schools are required to disclose details of their finances to the Department for Education, although not all of them do so, meaning only an incomplete picture is available.

The figures show 20 of the 137 (14.6 per cent) local authority-maintained schools in Oxfordshire which did provide information were in a financial deficit in 2022-23 – up from 17 the year before.

A school is in a financial deficit when it spends more than it earned when factoring in the previous year's balance.

This may not be representative of the entire Oxfordshire area, given just 45 per cent of local authority-run schools and nurseries provided relevant information.

Nationally, there was a significant rise in the number of schools running a negative budget.

Some 13.1 per cent of local authority-run schools in England had a deficit in 2022-23 – an almost 50 per cent rise on the year before.

Julia Harnden, funding specialist at the ASCL, said many schools must operate in-year deficits while identifying longer term savings because of stalling investment in education.

"While schools endeavour to do this without detriment to pupils, this inevitably impacts on provision, such as pastoral support, curriculum options and routine building maintenance," she added.

Oxford Mail: Ms Harnden continued: "Despite the Prime Minister’s promise that his main funding priority in every spending review will be education, schools and colleges received barely a mention in the autumn statement.

"This must be rectified in the spring budget to turn rhetoric into reality."

Paul Whiteman, general secretary of school leaders' union the National Association of Head Teachers, said schools slipping into a deficit "will have cut everything they possibly can first" to maintain a positive budget.

Mr Whiteman added: "The number of schools being forced into deficit shows that government funding of education is nowhere near where it should be for the level of demand that actually exists."

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Financial difficulties were especially problematic for nurseries, with almost a third in a deficit across England in 2022-23.

A Department for Education spokesman said: "School funding is rising to more than £59.6 billion next year – the highest ever level in real terms per pupil.

"While the vast majority of schools are operating with a surplus, we are providing up to £40 million in 2023-24 to support schools which find themselves in financial difficulties."