An education union boss has reportedly suggested a “week on, week off” approach to schools if student numbers need to be reduced.
The government plans for all children in England to go back to school full-time from next month.
Boris Johnson, the prime minister, called this a “national priority” in a newspaper article at the weekend.
The general secretary of the Association of School and College Leaders (ASCL), said: “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’.”
Schools shut for most students in March as part of efforts to contain the spread of coronavirus, staying open for children of key workers or vulnerable children.
However, some year groups, including Reception and Year 6, were allowed back from the start of June.
A government minister said last weekend the plan is still to get all children back in school by September, despite an education union raising concerns over recent lockdown rules in the northwest, and delays to the easing of national restrictions.
On Sunday, the UK reported more than 1,000 new coronavirus cases for the first time in more than a month.
Mr Barton from the ASCL told The Telegraph: “The majority of leadership teams will be thinking about different scenarios and how they can get some children to school.”
The union boss added: “In the absence of clear guidance from the government, leaders are making their own contingency plans”.
The UK prime minister has called it "morally indefensible" to keep schools shut for any longer than necessary.
Mr Johnson wrote in the Mail on Sunday this weekend: "Now that we know enough to reopen schools to all pupils safely, we have a moral duty to do so.”
He warned of the "spiralling economic costs" of parents and carers being unable to work and the potential damage to children's health if they do not return.