Norfolk schools are facing a £29m funding shortfall next year compared to 2015, despite political parties promising billions of pounds of more money, a union has claimed.
Around 82pc of schools in Norfolk and Waveney are projected to be more worse off next year than five years ago, with three schools seeing a loss of more than £500,000.
Just seven secondary schools out of 60 will receive an increase in real terms funding in April 2020, according to research by the National Education Union (NEU).
The figures come following reports of teachers having to use their own money to buy equipment for pupils and staff redundancies.
Over the summer Avenue Junior School, on Avenue Road, Norwich, asked parents to help with routine maintenance because of budget cuts.
Headteacher Debbie Dismore told parents that the school's "difficult financial position" had forced it to make cuts to all areas of spending, including the upkeep of its Victorian building.
Jobs which need completing included repainting, window-cleaning, pruning and hedge-trimming.
The funding shortfall of £29m amounts to a loss of £288 per pupil.
This figure also includes the additional funding of £2.6 billion for schools in 2020/21 announced by Prime Minister Boris Johnson, the NEU said.
Small primary schools are the worst hit.
Northrepps Primary School is set to lose the most with a real terms funding loss of £2,146 per pupil.
This was followed by Marsham Primary School, near Aylsham, with a per pupil loss of £1,554 and Catfield CofE Primary School with £1,514.
A survey of 55 teachers in Norfolk last year found 93pc bought supplies for their classrooms, while 62pc admitted they bought children items such as books, clothes and food and drink.
In 2017, another survey conducted by this newspaper of 75 headteachers found nearly nine in 10 schools had been forced to cut staff while 44pc reduced the number of, or hours of, teaching assistants.
Bob Groome, NEU Norfolk joint branch and district secretary, said there were still redundancies and re-organisations taking place.
"It is a shame that we are losing staff due to the schools not being able to afford to keep them," he said.
"There will have to be a cut-off point where they cannot make anyone else redundant. Class sizes are rising and there are cuts to teaching assistants which is sad for SEND [special educational needs and disabilities] children.
"Schools will be £2b poorer [since 2015] as of next year - that is a lot of money to take out of our kids' education."
Mr Groome said the issue was "not party political", adding: "We want to get the message out to parents and tell them to vote for whoever they think is going to be better for their children, and we have asked politicians to sign a pledge."
Alderman Peel High School, in Wells, topped the list for secondary schools with a projected per pupil funding loss of £926, based on a shortfall of £467,748 for 505 pupils.
Ormiston Venture Academy is facing the biggest deficit - it is estimated to lose £646,826 real terms funding in 2020, amounting to a loss of £746 per pupil, the second highest for a secondary school.
This was followed by Archbishop Sancroft High School, in Harleston, which is expecting a shortfall of £734 per pupil.
Only seven high schools - Wymondham High Academy, Acle Academy, Iceni Academy, SET Beccles School, Aylsham High School, Taverham High School and Wayland Academy Norfolk - have held onto or received improved funding since 2015.
With education to play a key issue in the run up to the general election, the main political parties have announced where they stand on spending for schools.
The Conservative Party have pledged to invest £14bn in the next three years, while Labour have said they will bring schools under the control of parents and teachers and close tax loopholes in private schools.
The Liberal Democrats are promising 20,000 extra teachers and to replace Ofsted with a new HM Inspector of Schools, and the Green Party pledged to increase funding for schools by £4bn a year and levy VAT on private schools.
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