Transport Secretary Grant Shapps has insisted the Government wanted people to wear masks on public transport - despite scrapping mandatory requirements to don a face covering from next week.
Mr Shapps added to confusion when he backed London Mayor Sadiq Khan's decision to make masks compulsory on the London Underground.
The top Tory said the decision was "very much in line" with what ministers wanted to happen, despite Boris Johnson's decision to lift legal restrictions on masks in England from July 19.
Mr Khan said he had been forced to make masks a "condition of carriage" on London's transport network as he was not prepared to put Londoners at risk.
Enforcement officers can kick passengers off buses and tubes for not wearing masks or bar them from entry under the rules.
The decision creates confusion for commuters, as masks will not be required on trains outside the capital from Monday.
Mr Shapps told Sky News: "Whilst we are going from this being a legal requirement to guidelines, we do expect individual carriers to make sure they are putting in place whatever is appropriate for their network."
He added: "The airlines have already said that you will need to carry on wearing masks on those.
"It is very much in line with what we expected - indeed wanted - to happen."
Mr Khan said around 400 officers would be enforcing the rules but admitted the scheme was not perfect.
He told ITV's Good Morning Britain: "Because we don't have national backing, we're going to make it a condition of carriage.
"This is an imperfect solution. We are working on passing a bylaw to make it a law too."
Conditions of carriage are contractual conditions between passengers and TfL, which include not consuming alcohol.
City leaders across the rest of England - including in Greater Manchester, Liverpool, Newcastle and Bristol - do not have the same powers but are understood to be in talks with local transport operators about encouraging passengers to wear masks.
The PM would have risked another damaging Tory revolt in the Commons if he had sought to maintain the legal order to wear face coverings.
