A parent has said she was "appalled and outraged" at being told her daughter's state school had a £60,000 funding gap.
St Matthew's Primary School's Parents Teachers Association has asked parents for monthly donations to help make up the budget deficit it faces.
"This is a state school, it should be funded by the state," added Donna, mother of seven-year-old Flora.
A government spokesman said Cambridgeshire had received a rise of 3.5% compared to its 2017 budget.
Tony Davies, head teacher said the complexities of education funding and higher costs meant the increase had not translated into extra cash.
The local education authority-run school has 680 pupils and its annual budget is £5.3m, he said.
Funding per pupil was up just £2 on last year and down £57 over five years. He said cuts were "beginning to bite" and the school had used up its savings with just £82 now left in reserves.
"We have already had to make cuts in computers and other classroom resources and it has had an impact on the provision of counselling services," he said.
Donna, whose daughter is in Year Two, said the issue of school underfunding was driving her "mad".
"This is about the future of not just our children but of the whole country . If education is not funded properly, what kind of future will this country have?" she asked.
In a statement, the Department for Education said an extra £20m had been given to Cambridgeshire's schools this year - a rise of 3.5%. But it did acknowledge the pressures on school budgets and said the department would back head teachers "as we approach the next spending review".
Simon Bywater, chairman of the Children and Young People committee on Conservative-run Cambridgeshire County Council, welcomed the cash, but said schools struggled with extra costs, including providing education for a rising number of pupils with special needs.
The report features on Sunday Politics East on BBC One at 11:00 BST on 23 June.