Sadiq Khan says not wearing a face mask on Tube should be criminal offence

Khan told the BBC's Newscast podcast that he was lobbying the government to "allow us to bring in a bye-law, so it will be the law again".

This will mean that those ignoring the rule can be fined, with the police and British Transport Police enforcing it.

"We need people to be coming back to the West End. We want to encourage people to return to their offices. They are not going to do so if they don’t feel public transport is safe," he said.

"I’m hoping the Government understands, on the issue of public safety and public confidence, we want to be able to use the law to make sure people do wear face masks in spaces where you can’t keep your social distance for obvious reasons."

Ahead of the PM's announcement on the latest lockdown rules, Khan's spokeswoman signaled his intentions to the press.

“Today the mayor has had discussions with the TfL commissioner, and both are clear that the simplest and safest option going forward would be for the government to retain the requirement for face coverings on public transport,” said Khan’s spokeswoman. “Should the government lift the requirement for mandatory face coverings on public transport, TfL will have discussions with other train operating companies and the DfT about next steps and how to ensure passengers have the confidence to use public transport.”