Teacher union bosses have been accused of trying to throttle government plans to reopen schools next month with a 200-long list of safety demands.
The National Education Union has provided its half a million members with a 'checklist' of Covid-secure measures which its institution should be enforcing.
If these demands are not met, and concerns are not acted upon, the union urges staff to 'escalate' their quarrel.
It comes as Geoff Barton, the general secretary of the Association of School and College Leaders, also warned that schools could teach pupils on a 'week on, week off' basis if the government continued to demand that all children return to school by September.
Mr Barton told : 'If you want to limit the number of children on site or travelling to and from school, a big part of that is using rotas and the obvious way to do it is week on, week off.'
The general secretary added that leadership teams would be drawing up their own plans in the absence of clear guidance from the government.
The 200-long list of safety demands asks if the timetable includes sufficient creative subjects, and space for dialogue and sustained thinking?
The list of demands also questions if lidded bins with double bagging be available in every classroom.
MPs last night branded the 24-page document a 'wrecker's charter' which could thwart the PM's 'national priority' for classes to resume (pictured at The Discovery School in July)
He added: 'The majority of leadership teams will be thinking about different scenarios and how they can get some children to school. In the absence of clear guidance from the Government, leaders are making their own contingency plans.'
Last night MPs ripped into the 25-page 'wrecker's charter' by the NEU which they said could thwart the Prime Minister's 'national priority' for classes to resume.
Education select committee chair Robert Halfon MP branded the criteria 'impossible' and told the Sun on Sunday: 'It is incredible not one of these 200 nitpicking questions asks the most important thing of all - what's best for the kids?