The NUT could delay its plans for a national strike to allow teachers to take action alongside support staff, TES has learned.

Teaching assistants and other school staff who are members of public sector unions Unison, Unite and GMB are to be balloted for strike action, after a 1 per cent pay offer was overwhelmingly rejected by their members.

After three consecutive pay freezes for local government employees, followed by two years of below-inflation pay rises, Unison has hit out at the latest offer as “effectively another pay freeze”. The ballot being held by the union, which has almost 250,000 members in schools, starts next week.

If members back the plans, industrial action will start in July, with 10 July having been widely mooted as the likely date. No date has yet been officially announced by the unions.

At its annual conference last month, the NUT decided to hold a national walk-out in the week beginning 23 June, but TES understands that some members of the union’s executive are keen to delay the strike so they can coordinate action with the other unions. Joint action by the NUT and the support staff unions would cause significant disruption to schools across the country.

NUT executive member Martin Powell-Davies, who next month will take on general secretary Christine Blower for the leadership of the union, said it was “very likely” the strike would be delayed. The prospect of joint action with other unions would increase the pressure on the NASUWT to take part, he added.

“The union hasn’t yet made a decision on it, but I think it’s looking very likely,” he said. “That will ask questions of the NASUWT leadership. If there are unions that don’t want to take action, I’d be very keen to make sure that we’re taking action alongside the unions that are.

“The executive’s got to decide, but it’s something I’d support for the sake of a couple of weeks [delay]. It will certainly help support staff if teachers are taking action alongside them, and it will help us as well.”

Jon Richards, Unison’s head of education, said no plans would be announced until the union’s ballot has ended.