I would suggest another minefield. Under contract law, you cannot make terms retrospective. Therefore if they were to introduce masks as such, some would, some wouldn`t have to comply depending on when you entered into contract with them and on the same flight..Complete farce. In addition to which foreign Governments domestic legislation re masks(ie Irish Reg Aircraft) has no validity in the UK and is not enforceable.
Interestingly the Rail Industry have tonight said they will not enforce masks on trains...