The National Education Union (NEU) said that the first strike would be on 1 February, a date when 100,000 public sector workers are due to strike in what could become Britain’s biggest day of coordinated industrial action for decades.

In all, 23,400 schools in England and Wales will be affected by the school strikes. Teachers in Scotland have already held strikes which have closed many schools.

Sunak is coming under increasing pressure to try to resolve pay disputes with hundreds of thousands of workers following months of strikes which have caused widespread disruption.

With inflation running at more than 10%, workers from multiple sectors are demanding higher wages.

The NEU, Britain’s largest education union, with around 500,000 members, said the government had offered its members a 5% pay rise which it says equated to a pay cut. Low pay for teachers has pushed many to leave the profession, the union said.

“This is not about a pay rise but correcting historic real-terms pay cuts,” NEU general secretaries Mary Bousted and Kevin Courtney said in a joint statement.

The government has said it cannot afford big wage rises and warned that any big boost to salaries would exacerbate the inflation problem.

Education minister Gillian Keegan said it was “deeply disappointing” that the NEU had voted to strike.

“Talks with union leaders are ongoing and any strike action from one union will have a damaging impact on pupils’ education and wellbeing,” she said in a statement.

Some 90% of the NEU teachers voted to strike in England on a turnout of 53%, the union said, meeting the legal turnout threshold for action to proceed. In Wales, 92% voted yes to action, on a 58% turnout.

Last week, a strike ballot by a different teachers’ union in England fell short of the required turnout threshold. On Monday a separate union for head teachers said it was considering re-running a ballot on industrial action after it also missed the threshold for strike action, possibly due to postal disruption.

Teachers in England last held a strike in 2016, but the majority of schools remained open. A larger-scale walkout by teachers took place in 2008.

The strikes will take place over seven days in February and March, though any individual school will only be affected by four of them, the union said.

(Reporting by Sarah Young and Alistair Smout, additional reporting by Kylie MacLellan and Farouq Suleiman; Editing by Janet Lawrence and Alison Williams)