Since the election date for next year’s London mayoral election was announced, Sadiq Khan has been putting on a show of confidence that his re-election is in the bag with his supporters pointing to polling that suggests Labour enjoy a 40-point lead in the capital. However, the Ulez expansion – which Keir Starmer blamed on his failure to take Uxbridge in last month’s by-election – has certainly put a spring in the step of his Tory mayoral opponent Susan Hall.