Several airlines will continue to require passengers to wear face coverings even if the Government drops the legal requirement to do so.
Ryanair said it will not change its current policy, while the PA news agency understands that easyJet is also not planning to ease its rules.
Train operators have pledged to “support” passengers who continue wearing face coverings if they become voluntary.
Boris Johnson is expected to announce on Monday that face coverings will no longer be required in many settings in England from the final step of the Government’s road map out of lockdown, due to take place on July 19.
A spokeswoman for Ryanair said face coverings “will still be mandatory across all Ryanair flights, regardless of the departing/destination country”.
She added that this is in line with guidance from the European Union Aviation Safety Agency (Easa) and the European Centre for Disease Prevention and Control (ECDC).
PA understands that easyJet has no plans to make any changes to its requirement for passengers to wear face coverings, but is keeping the policy under review.
A spokeswoman said the airline is guided by its in-house medical adviser and a number of key bodies such as the World Health Organisation, Easa and ECDC.
She added: “At present their guidance around the wearing of masks onboard remains unchanged.”
The Rail Delivery Group (RDG), which represents train companies, said trains should be “treated consistently with other indoor settings when it comes to the removal or ongoing use of restrictions”.
It called for “any decision to leave public transport behind other parts of the economy” to be “based on the science”.
If the wearing of face coverings on public transport becomes voluntary, operators would “support people who wish to continue wearing one”, the RDG added.
Even if the Government eases the rule on face coverings on public transport, some organisations could make them a condition of carriage.
Greater Manchester mayor Andy Burnham urged the Government to retain the requirement to wear a face covering in “locations where people don’t have a choice to go”, such as public transport and supermarkets.
But he told BBC Radio 4’s World At One programme that he would not make them mandatory on Manchester’s tram network as “I just don’t think it would work”.
“If the Government comes up with a national ruling I just don’t see how we would be able to enforce it at our level,” he said.
The situation in London is complicated by the Government’s recent bailout of Transport for London (TfL), and the fact that many passengers use a combination of TfL services and mainline rail.
A spokeswoman for mayor of London Sadiq Khan said: “On the continuing wearing of face masks, it is important that we continue to follow the science around the extent to which they limit transmission on transport and in busy indoor spaces.
“Evidence shows that the wearing of face masks gives many Londoners the confidence that they can travel safely on public transport.
“People feeling confident they can travel on our Tubes, buses and trains as they get busier will be a vital part of encouraging more people into central London as restrictions are lifted further, and it is something that we will continue to look at closely.”
Trade union Unite, which represents tens of thousands of public transport workers, claimed it would be “an act of gross negligence by the Government” to end the requirement to wear face coverings on public transport in two weeks.
Care minister Helen Whately was asked on BBC Radio 4’s Today programme if she would continue to wear a mask when commuting by train from her constituency of Faversham, Kent, to London.
She replied: “I think it’s the sort of environment where, if something’s crowded, I think I might.”