Teachers at a girls' private school could go on strike because of plans to leave a pension scheme.

Staff at Northwood College for Girls are among 23 schools within the Girls' Day School Trust that could be involved in the first ever national ballot on strike action in the trust’s 149-year history.

Members of the National Education Union (NEU) will vote in an indicative ballot on whether to launch strike action over the trust's plans to leave the Teachers’ Pension Scheme.

The proposal to leave the scheme would leave remuneration in the group of private schools significantly worse than local state schools, the union says.

It warns that a "talent drain" from the trust's schools schools is likely as staff may leave to protect their retirement.

A number of independent schools have withdrawn from the teachers' pension scheme, or are considering a withdrawal from the scheme, after the rate of employers’ contributions increased by 43 per cent in 2019.

The uplift has been covered by the Government in state schools, but not in private schools.

Kevin Courtney, joint general secretary of the NEU, said: "The proposal by the Girls’ Day School Trust to leave the Teachers’ Pension Scheme (TPS) is an unnecessary decision.

"There is no imperative reason to leave the scheme. The Trust’s finances are healthy as can be seen in their public accounts.

"No evidence to the contrary has been provided to staff or their recognised union, the NEU."

He added: "We continue to engage with the employer and sincerely hope we can persuade the trust to withdraw their plan to remove our members’ pension rights under the Teachers’ Pension Scheme."

The indicative ballot of almost 1,400 staff across the 23 private schools will run from November 22 to December 6.

It comes after the GDST began a consultation with staff and the NEU across its independent schools in September over the proposal to leave the scheme.

Cheryl Giovannoni, chief executive of the GDST, said: "The GDST has been grappling with the increased cost of the TPS scheme since 2019, when the employer contribution increased from 16.48 per cent to 23.68 per cent.

"We are not alone in having to respond to the additional costs; 280 schools in the independent sector have already left the TPS.

"Our priority is to do the very best for teachers across all our schools, and to ensure the long-term sustainability of the GDST."

She added trustees are proposing an "excellent alternative" to the TPS and said the trust would not have proposed to leave the scheme if it felt it did not have a "viable alternative" for teachers.

Ms Giovannoni added: "To ensure transparency, we have shared in detail our case for change and extensive consultation material with our teachers as well as the NEU."