LONDON—Mask-wearing will be required on London’s transport network even after the legal obligation to wear them in England is lifted on July 19, the city’s mayor said Wednesday. Sadiq Khan has asked the body that oversees transport in the capital to enforce the use of mask wearing on the subway, buses, and trams as a “condition of carriage”—basically contracts between passengers and Transport for London. Khan said he is “not prepared” to put transport users “at risk” by removing the rules on face coverings after legal restrictions are lifted next Monday despite a big resurgence of the virus across the UK as a whole. Under the new approach outlined by Khan, enforcement officers would be able to deny access or eject passengers not wearing a mask while using the subway, buses, and trams. London’s Metropolitan Police and British Transport Police won’t be able to get involved, though, as mask-wearing will …