The NASUWT teaching union has been involved in action since last December, but has decided to escalate its campaign in the form of a strike today.
Chris Keates, General Secretary of NASUWT, said:
The escalation of the NASUWT industrial action is entirely the responsibility of the Secretary of State for Education, Michael Gove.
This action has been specifically designed to be pupil, parent and public friendly. We are endeavouring to ensure that is still the case with our escalated action.
The Secretary of State continues to fail genuinely to engage with the NASUWT and continues with his reckless disregard of the deep concerns of the teaching profession. This is a betrayal of not only the workforce but of every child and young person.
More top news
Nadeem Muhammad, 43, was convicted of possessing an explosive with intent to endanger life after a pipe bomb was found in his hand luggage.
Princes William and Harry will officially mark the 20th anniversary of their mother's death by visiting the garden created in her name.
Holidaymakers risk fines of up to £125 if they fail to meet the new clean air rules, but only a third are aware of the regulation.