Almost two dozen schools in Gloucestershire were in a financial deficit in the last academic year, new figures show.

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.

Department for Education figures show 23 local authority-maintained schools in Gloucestershire were in a financial deficit in 2022-23.

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

It meant 12.2% of the 189 schools who provided financial information ran at a deficit last year – up from 10.4% the year before.

The same schools may not have submitted sufficient information each year.

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

Some 13.1% of local authority-run schools in England had a deficit in 2022-23 – an almost 50% 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.

Ms Harnden said: "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."

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

A Department for Education spokesperson 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."