… Street for the first time as prime minister on July 24 after returning from Buckingham Palace, Boris Johnson made it … 31, 2020 or, with an extension, Dec. 31, 2021 or Dec. 31, 2022] as part of the future relationship. And third, he said … might enable Johnson to remain in 10 Downing St. until the next scheduled election in 2022, and perhaps even later, …