School-cuts campaigners have publicly projected details of nearly 18,000 schools that they say are facing funding cuts, as part of a push for more money in today’s Budget.

The Palace of Westminster and the Treasury were among the sites targeted by the School Cuts coalition last night in the hope of plugging what they said was a £2 billion shortfall in school funding.

The projections listed the names of 17,942 schools in order of the severity of their financial pressures.

The coalition includes the NEU teachers’ union, NAHT heads’ union, Association of School and College Leaders, GMB, Unison and Unite. 

“If the chancellor continues to ignore the real-terms cuts to school funding, headteachers, governors and school staff have together warned there will be long-term damage to children’s education,” the unions said in a joint statement.

“While the government continues to claim there is more education funding than ever before, the UK Statistics Authority has issued direct warnings to the Department for Education to stop misrepresenting data that is potentially misleading to the public.”

The School Cuts coalition has set the chancellor six tests that it says must be met in the Budget. 

Schools have been under increasing financial pressure in recent years, with widespread evidence that many are axing staff, dropping subjects and increasing class sizes as a result.

Analysis by the independent Institute for Fiscal Studies found that funding has fallen by 8 per cent in real terms when cuts to local authority services are taken into account.

The Department for Education has routinely argued that more money is going into schools than ever before, but has been reprimanded by the UK’s statistics watchdog for its misleading use of figures.

Chief secretary to the treasury Liz Truss this weekend insisted that education standards were improving and British schools were “now amongst the leaders in reading across Europe”.

Responding to a question about the squeeze on per-pupil spending, she said: “It’s going up in real terms…and we put an extra £1.3 billion into education last year.”

The Autumn Budget has been moved from its usual slot to avoid a clash with Halloween, and will be delivered this afternoon.