“Austerity-hit schools could be facing an eye-watering £4.8bn cuts bombshell if the government doesn’t fund a planned pension contributions hike.

Headteachers will be left with no choice but to slash spending on “the absolute basics” if Chancellor Philip Hammond does not plug the four-year shortfall at next year’s spending review, Labour has said.

The new figures, from the House of Commons Library, will pile pressure on ministers to act in the wake of a mass protest at Westminster by headteachers in September.

The Department for Education (DfE), however, said that the changes make teachers’ pension schemes “sustainable in the long-term”. …

In 2016, ministers admitted the pensions shortfall would amount to a sizeable £2bn, but that figure was revised up at the November budget and there is only enough cash set aside to cover costs for 2019/20.

It comes after respected think tank the Institute for Fiscal Studies (IFS) found that per-pupil funding had fallen by 8% since 2010.

Labour MP Stephanie Peacock, who is a former teacher, said the government should match the commitment it gave to the NHS, which has seen its extra pensions contributions fully covered.