Devon faces a £28m black hole in its budget and could go into the red for the first time in a generation, councillors will be told.
A report to Devon County Council's (DCC) cabinet meeting tells councillors that the total projected budget overspend, four months into the 2019/20 financial year, is £4.3m.
However, Mary Davis the county's treasurer, says this figure assumes a funding shortfall of £15.8m for special educational needs and disability (SEND) will not be dealt with this financial year.
It also assumes planned contributions to reserves of £8m are not made.
The report said that, without these adjustments, the projected overspend would be £28.1m.
Mrs Davis' report added: "The Government has announced additional funding for SEND in 2020/21 but nothing as yet for the current year.
"It is suggested that the deficit is not dealt with at the end of this financial year but held on the balance sheet as a negative reserve.
"It is not a solution, but it is a mechanism that gives more time for a solution to be found."
The cabinet are recommended to note the budget monitoring forecast position.
Councillor Alan Connett, leader of the Liberal Democrat group, said the projected £28 million shortfall highlights that Devon is being 'short-changed' by this Government.
He added: "More children and adults need the council's support.
"Our schools are being cheated.
"They get around £300 per child less than the national average, and our children with special educational needs are being let down.
"Those that need our help the most are being denied by a Government that could act, but won't."
The cabinet agenda report says DCC could receive an extra £11.7 million next year and £9.5 million in 2021/22 for education, following the Government's spending review, and an extra £8.6 million to help support children with special needs next year.
County council leader, Cllr John Hart, said: "We have been campaigning with headteachers, governors and parents for fairer funding for Devon's schools and the promise to 'level up' under-funded areas is one I very much welcome.
"It's also encouraging to see Mr Javid (Chancellor for the Exchequer) announcing a three-year funding cycle for education as compared to the single year for other services."