Members of the National Union of Teachers (NUT) are launching a campaign of action short of a strike, joining those in the NASUWT who are already taking action.
Industrial action by teachers over issues including pay, pensions and workload will be stepped up today amid warnings of an escalation in the coming months.
More top news
Molly Smith, 5, won £500 after her accidental selfie with a snowman caught the attention of competition judges.
Harry Street, formerly Barry Williams, shot dead five people in a spree across the West Midlands in 1978.
The Interview, the Sony film about a fictional plot to assassinate North Korean leader Kim Jong Un, has made more than $15m in online sales.