The decision comes after the Pocklington School Foundation confirmed it will be removing teaching staff from the Teachers’ Pension Scheme (TPS).
Members of the National Education Union (NEU) and the NASUWT will be taking strike action before Easter, an NEU spokesman confirmed.
The spokesman also said that the teachers were being asked to sign new contracts and any that would not sign would be subject to ‘fire and rehire’ proceedings.
The spokesman said: “The removal from the TPS will leave remuneration in the school worse than local state schools and is likely to be a contributing factor in poor recruitment and retention of teaching staff.
“In order to implement this change, the school has stated it will use a fire and rehire tactic to change the conditions of the members of staff who are unwilling to sign new contracts.
“The NEU was committed to consulting with the school in hope that we could persuade the Governing body of the Foundation that withdrawing from the TPS was a strategic mistake. There is no imperative reason to leave the scheme.
“The Foundation’s finances are healthy as can be seen in its public accounts.
“The NASUWT, a sister union at the School, has also concluded its formal strike ballot with members voting in favour of action.
“Strike action will be undertaken in the near future, and a list of dates will be published when the school has been notified.”
A Pocklington School Foundation spokesman said: “Members of two teaching unions (the NEU and NASUWT) at Pocklington School have been balloted, consistent with other disputes at independent schools, and voted in favour of industrial action. This arises from a collective consultation process the foundation has recently concluded with teaching staff regarding membership of the Teachers’ Pensions Scheme.
“The foundation entered this consultation process to control future costs and mitigate potential risks attached to the TPS.
“At the current time, roughly 300 independent schools have already exited the TPS, or are planning to do so.
“Following detailed discussions with teaching staff and their representatives, the Governing Body believes that the new proposal will best meet the long-term needs of the foundation by providing certainty and stability, whilst offering a generous pension provision and benefits package.”
Tim Stephenson, chair of the governors, added: “We are disappointed that some teachers have decided to vote in favour of industrial action after we have worked so hard to provide a generous pensions solution.
“We would like to reassure parents that any disruption to children’s education will be kept to an absolute minimum.”