The NUT and NAHT unions will go ahead with a joint ballot to boycott Sats tests for 11 year olds.
Both unions passed motions backing a ballot at their conferences last year.
The government has abolished Sats tests for 14 year olds but seven and 11 year olds still face them.
Yes votes in the ballots would mean that children would have a normal week’s teaching instead of sitting the tests.
The tests are due to take place in the week beginning 10 May.
The ballot will begin in March.
“With the action due straight after the expected general election, this will no doubt become a hot topic during the election campaign,” said Nick Grant, an NUT executive committee member.
The NUT and NAHT should organise joint rallies to put the case against Sats, involve parents and students in the campaign and to build the yes votes.