Private schools are facing a wave of strikes over changes to teacher pensions, a union has revealed as new data shows up to one in ten fee paying institutions plan to leave the Government-backed scheme.

The majority of private schools are part of the Teachers’ Pensions Scheme (TPS) and are being forced by the Treasury to step up their payments by 48 per cent.

The increase in employer contribution, from 16.48 per cent of teachers’ salaries to 23.6 per cent, is “unaffordable” for many schools, some of whom are having to pull out of the scheme altogether, the Independent Schools Council (ISC) has said.

The hike followed a valuation of the public service pension schemes by the Treasury. The Department for Education (DfE) is providing funding to help state schools meet the extra costs for at least the first year of the new scheme, but private schools will need to foot the bill themselves.

Now the National Education Union (NEU) is warning that teachers at fee paying institutions are considering strike action amid fears that they will be put on to private pension schemes with worse terms.

John Richardson, of the NEU teaching union which represents around 40 per cent of the teachers affected, and that leaving the scheme would be a “massive, massive detriment” to members, who would be placed on less favourable pension schemes.