Boris Johnson has pledged to remove the “legal obligation” for people in England to wear a face mask.
It is one of numerous mitigations which will be dropped at the end of the coronavirus lockdown, currently planned for 19 July.
However, some people might not want to throw away their masks just yet.
Johnson, speaking at Monday's Downing Street press conference, added “guidance will suggest where you might choose to [wear a mask] especially when cases are rising, and when you come into contact with people you don’t normally meet in enclosed spaces such as crowded public transport”.
Speaking at the same briefing, England’s chief medical officer Professor Chris Whitty appeared sceptical about the prime minister's decision to scrap the requirement.
Watch: PM outlines five-point COVID plan
He pointed out the “epidemic is clearly significant and rising”, and set out three scenarios in which he will choose to wear a mask.
1. Any indoor situation where it is crowded
“That is because masks protect other people,” Prof Whitty said. “This is a thing we do to protect other people – by far its principal aim.”
2. When required to by a 'competent authority'
Even though the government will remove the legal obligation nationally, individual transport authorities, for example, could still decide to make face masks a condition of travel.
Transport for London said earlier that it's an issue "we will continue to look at closely".
Individual shops could also still choose to make face masks a condition of entry for customers.
Prof Whitty said of being asked to wear a mask by a “competent authority”: “I would have no hesitation about doing that, and I would consider that a reasonable and sensible thing if they have good reasons.”
3. If someone else is feeling uncomfortable
Prof Whitty said: “As a point of common courtesy, of course I would wear a mask.”
It comes as a new YouGov poll, released at the same time as Johnson’s speech on Monday, suggested 71% of people believe face masks should continue to be mandatory on public transport once restrictions are lifted.
The survey also estimated 66% of people believe masks should continue to be required in shops and some enclosed public places when lockdown ends.
Watch: Should face masks be worn past 'freedom day' on 19 July?