Schools are being urged to boycott baseline testing of reception children this September while the National Union of Teachers executive considers a ballot for a wider boycott of all primary testing in 2017.

The NUT’s annual conference in Brighton has passed a motion calling on schools not to complete baseline tests for reception children this autumn, and calling on education secretary Nicky Morgan to cancel this summer’s primary school national tests, or at least “not to rely on the data” if still going ahead.

The union’s executive also said a boycott of all key stage 1 and 2 testing may be needed, and has agreed to “consider” a ballot for a boycott of the summer 2017 tests “as part of a wider campaign to raise awareness of the risks of testing”.

The NUT has also pledged to work with other bodies opposed to testing to mount such a campaign.

Members of the NUT have already made their opposition to testing well-known. In a survey of primary teachers conducted by the union, 86 per cent of respondents said they were in favour of scrapping new primary tests.

Teachers have complained that new tests are too hard and not age-appropriate for pupils, while a lack of clarity over the future of baseline tests is also a concern.