Passengers who do not wear face coverings on public transport can have “reasonable force” used against them by police.
Announcing the rule change earlier this month, transport secretary Grant Shapps warned: “You could be refused travel if you don’t comply, and you could be fined.”
The Department for Transport rules can be enforced by police and transport staff with fines of £100.
They will also have powers to stop people who are not wearing face coverings from travelling and can use “reasonable force” to remove someone who refuses to do so.
Shapps said: “I expect the vast majority of people won’t need to be forced into this, because wearing a face covering helps protect others.”
The new rules came into effect on Monday as more lockdown measures were eased in England despite the coronavirus “R rate” – the level of the spread of infection – rising above 1 in some parts of the country.
Non-essential shops were allowed to reopen on Monday and many secondary schools reopened to pupils.
The guidelines do not apply to people entering shops, despite the government having previously advised people to wear face coverings in enclosed public places.
And passengers are allowed to remove their face coverings to eat or drink while on public transport.
Children under the age of 11 do not have to wear face covers, and the penalties will not apply to on-duty police or public transport staff.
The regulations, which cover bus, coach, train, tram, ferry and aircraft passengers, say face covers can be removed if it is “reasonably necessary” for a person to eat or drink or if they rely on lip-reading to communicate.
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