Thousands of teachers could be set to walk off the job as the National Education Union (NEU) prepares to announce the result of a strike ballot today.
The NEU has said walkouts in England and Wales could begin at the end of the month after more than 300,000 teachers and support staff were asked to vote in a dispute over pay.
The union will have to give two weeks' notice of any industrial action.
A ballot of members of the NASUWT teachers union last week failed to reach the 50% turnout threshold, although nine in 10 of those who did vote backed strikes.
Members of the Educational Institute of Scotland union are beginning 16 days of rolling strike action today, with teachers in two of Scotland's 32 local authority areas walking out each day until 6 February.
