Schools across Birmingham and the West Midlands could close to pupils in the autumn after the two biggest teaching unions joined forces to protest over pay and workloads.
The NASUWT and the NUT, representing nearly nine out of ten teachers between them, have threatened national co-ordinated strikes against Government “attacks” on jobs and pensions.
The unions have signed an agreement, which will see them jointly campaign over the issues.
Birmingham has a 7,000-strong NASUWT membership, the largest in the country, while there are more than 5,000 NUT members.
NASUWT general secretary Chris Keates said the city would be key to the campaign.
She said: “Birmingham has always been our biggest branch and it is the largest metropolitan education authority, so clearly it will be at the centre of all that we are trying to do.
“Since the Government came into office, there has been a relentless and unprecedented assault on teachers’ pay and conditions of service.
“This assault on teachers is damaging standards of education.
“Our two unions, which represent the overwhelming majority of the teaching profession, are united in our determination to defend education by protecting teachers.”
News of the national campaign comes a week after the two unions suspended proposed strike action amid claims Birmingham primary schools are being “forced” to become academies.
NASUWT and NUT members at 13 primary schools had been balloted over controversial proposals to take them out of local authority control.
But union bosses said they felt it was not “appropriate” to go ahead until they had discussed the academies issue with the new Labour-controlled Birmingham City Council.
The NASUWT has been taking action short of a strike on pay, jobs, workload and pensions since last December. The NUT will now hold a fresh ballot for industrial action, with the result due in the autumn term.
Ms Keates urged city parents to support the campaign. She said: “I’d ask parents to recognise that our two unions represent nine out ten teachers and we are taking this stand because we want to avoid strike action.
“We would ask parents to support us in getting the Government to listen by writing to their MP or the Secretary of State.”