Reopening UK schools on June 1 is too early, according to UK's Scientific Advisory Group for Emergencies (SAGE).
A two-week postponement would instead "halve" the health risk to children and also "allow greater time to set up an effective test, trace and isolate programme in all areas", the independent governmental advisory body said.
SAGE outlined its proposal in a draft report published on Friday, May 22.
The report also says that local innovation is required to provide educational opportunities for all children, with suggestions including requisitioning of community facilities, sports clubs, school playing fields, and football stadiums for use by schools.
UK Education Secretary Gavin Williamson said on May 16 that primary school children in reception, year 1 and 6 - as well as secondary school pupils in years 10 and 12, would be those returning to school first, but in smaller classes.
Williamson said children will be kept within those smaller groups, while schools will also see "rigorous" standards around hygiene and cleaning.
"This includes reducing class sizes, making sure pupils stay within these small groups, creating a protective and small bubble around them", he said.
SAGE is holding a public consultation on Friday, May 22, in partnership with the British Medical Journal and Mumsnet, taking questions from the public that will feed into a final report due to be presented to the Government next week.
The event is being live-streamed on SAGE's YouTube channel.