The Government has been told they must consider placing London in Tier 3 restrictions by scientists.
Around three quarters of the 32 boroughs have seen a rise in cases up until December 4, particularly among secondary school-age children.
But keeping schools open is the “number one priority,” Professor Paul Hunter, from the University of East Anglia, told Radio 4.
“I would put protecting our children’s education as the number one priority, above the need to control Covid, because the damage from inadequate education and disruption from their education is something that could last for our children’s lives,” he said.
Mass testing is to be rolled out in schools across the capital, as ministers launched a last ditch effort to avoid closures, The Telegraph can reveal.
Staff, students and families in secondary schools and colleges in parts of north-east London, are being urged to get tested.
The London boroughs receiving additional testing are: Barking and Dagenham; Hackney and the City; Havering; Newham; Redbridge; Tower Hamlets and Waltham Forest.
In north-east London, an additional 44,000 home test kits will be made available for school staff.
Fifteen mobile testing units will be deployed in or near schools in the worst-affected boroughs of the capital for staff, students and their families to be tested, the Government has said
Schools and colleges will be provided with information on how to get involved, and parents will be able to apply for tests using the online testing portal.
It comes amid growing concern over outbreaks in schools the week before the Christmas relaxation of rules where children are likely to be mixing with grandparents.
Though, schools will not be permitted to close early in an attempt to reduce the spread of Covid-19 before Christmas after Government ministers have threatened on Dec 11 to take legal action if they did.
Under the current system, a move to Tier 3 would not automatically close schools.
Tiers will be reviewed on Dec 16 and London Mayor Sadiq Khan said that unless people stuck to the rules, “tougher restrictions” could be imposed.
Khan released a joint statement with Cllr Rachael Robathan, leader of Westminster City Council on December 12, as Londoners flock to shopping districts ahead of Christmas.
“We are appealing directly to Londoners – when out shopping it is essential that you follow the rules. You must wear a face covering in shops and keep a two-metre distance wherever possible. We have worked to make the West End Covid-secure with wider pavements – including making Regent Street car-free on Saturdays – and regular signage to help Londoners keep their distance.”
A senior Whitehall source said no decision had yet been made, but warned that cases were expected to continue to rise due to the impact of people shopping and eating out after the second national lockdown.
However, Professor Tim Spector of King’s College London, has said moving London into Tier 3 would be a “total disaster” and trigger a last hurrah that would lead to an increase in cases.
The Prime Minister acknowledged London’s high Covid-19 case rate, which is now the second worst in the country, during a visit to St Guy’s Hospital on December 8 (see video below).