National Education Union
The call comes after Gavin Williamson was forced to make yet another u-turn on Friday, with all primary schools in London to remain closed after Christmas.
Announced on the eve of the Christmas break, schools have been left hanging as they wait for the details on the education secretary's plan.
Exclusive: Mayor of London warns ministers' words leave teachers exposed to greater verbal and physical abuse at hands of pupils and parents.
Parents, teachers, unions and politicians all have strong views about whether schools should shut. Read these arguments before you decide.
NEU surge is part of wider spike in trade union activism as workers seek better health and job protection
Fears over safety as trade unions prepare united front against "wildly optimistic" timetable.
Stress has seen children vomit and flee exam halls in tears.
Pupils across the country are picking up their results this morning.
Plans to create new grammar schools across the country are now firmly dead in the water
'The test will tell teachers nothing they don't already know'.