The NEU teaching union is delaying the release of a crucial ballot result that will show whether its members support a boycott of Sats.

At the same time as the national key stage 2 Sats results are released tomorrow, the NEU is due to publish some details of an indicative ballot, which took place over the last month.

But Tes understands they do not relate to a specific question as to whether the union should go forward with a full ballot for industrial action with a boycott of the controversial primary school tests.

NEU joint general secretary Mary Bousted said the results of that question would be referred in full to the union’s national executive on Saturday before they are made public. She said: “It will be up to the executive to make the decision on whether we decide to take action, if any.”

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Feelings ran high among certain sections of the union membership at its annual conference in the spring when a motion calling for the ballot on a Sats boycott was originally declared lost by what appeared to be a narrow margin.

Emotional pleas for a digital recount resulted in it being passed by 56 per cent against 43 per cent of the vote.

Labour leader Jeremy Corbyn received a standing ovation at the conference the following day when he said he would ban Sats if he came to office.

And shadow education secretary Angela Rayner told journalists at the conference that “parents needed to be weaned off Sats”.

Tes understands part of the result of the ballot will be released tomorrow, but they will not cover the results of the question asking whether primary school members support industrial action.

Schools minister Nick Gibb said tests had been part of school life since the ‘90s and were “pivotal in raising standards in our primary schools”.

He said: “They help to ensure children leave primary school with a secure grasp of the fundamentals of reading, writing and maths, which lay the foundations for success at secondary school and beyond, and allow teachers to track pupils’ progress as they go through the school system, making sure pupils stay on course to reach their full potential.

“Abolishing these tests would be a terrible, retrograde step. It would enormously damage our education system and undo decades of improvement in children’s reading and maths.”