SADIQ Khan has called for people to be forced to wear face coverings in shops and all confined public spaces.
The London Mayor has written to the PM to demand masks and coverings are used in more places than just public transport.
Mr Khan, a vocal supporter of widespread use of face masks and coverings, said Londoners had shown their willingness to wear them and they should be made compulsory as lockdown restrictions ease and non-essential shops reopen.
He said: “We have significantly reduced the number of COVID-19 cases in the capital.
“But the virus is still out there and as restrictions are eased it is vital that we do not become complacent and that we all continue to do everything we can to prevent a devastating second wave.
He said it was “increasingly clear” face coverings would be a “key” part of stopping the spread of the virus and they should became a “regular part” of Brits lives.
Earlier this week, he warned Brits wearing masks should be the “norm” for at least a year.
New measures making masks and coverings mandatory on public transport came into force on Monday.
Anyone going on a train, tube, bus, ferry or plane must cover their face up.
If they refuse, they could be denied entry onto public transport, or face a £100 fine.
Mr Khan added: “The high level of use on our public transport network has again shown that Londoners are willing to act to protect their community, but the Government’s current rules are lagging behind other countries.”
“With non-essential shops now opening and the public returning to our high streets, I urge the Government to follow WHO guidance and make these coverings mandatory for those shopping in retail outlets and in other spaces where it impossible to keep a safe distance.”
The World Health Organisation (WHO) has updated its guidance and recommending the use of face coverings in various settings.
The Government has said they will keep the face coverings rules under review – meaning they could last for an indefinite period of time.
The London Mayor gave himself a 10 per cent pay cut – £15,000 of his £150,000 salary – this week, as he tried desperately to fill a black hole in the capital’s budget.
He will freeze the pay of 15 of his political appointments too to help pay for the coronavirus crisis.
He demanded the UK Government step up with more funding for London – just weeks after a huge multibillion pound deal was signed off by ministers.