The NUT union has threatened a national strike unless the government ends the freeze on teachers’ pay.

At the union’s annual conference in Cardiff, delegates voted to “campaign for, and when there is the necessary support, ballot for a national campaign of strike and non-strike action, seeking the involvement of other teaching unions and non-teaching unions as appropriate if no progress is made in talks with the government”.

The union has called on the government to end the 1 per cent public sector pay cap and commit to restoring real terms pay losses suffered by teachers since 2010 “over as short a period as possible”.

The government has said public sector pay awards will be limited to 1 per cent a year to 2019-20, and in her submission to the School Teachers’ Review Body, the education secretary Justine Greening said the body must continue to consider its options within this context.

The STRB’s recommendation to the Department for Education is expected shortly.

Kevin Courtney, the NUT’s general secretary, said: “At a time of a crisis in teacher supply and a buoyant graduate recruitment market, the government needs to do much more to make teaching an attractive profession.”

On Saturday NUT delegates voted to call a one-day regional strike in the summer term, over school funding cuts.

And yesterday the union paved the way for a potential boycott of Sats in 2018.

Tomorrow delegates will vote on a motion to ballot members “on a boycott of all summative testing within primary schools”