IN SEPTEMBER 2015, Sadiq Khan was a recently re-elected MP, with a record-winning margin, and the front runner in the race to be London Mayor. He should have been elated. But he was heartbroken. His GP had just revealed that he had developed adult-onset asthma, aged 43.
A year earlier, he’d completed his first London Marathon. “I finished in good time,” he recalls fondly. “More importantly, I beat Ed Balls!”.
But, in the months that followed, he had found himself wheezing after a run, developed a cough and felt increasingly run down. He’d put it down to working too hard. But the diagnosis showed it was a lung condition brought on by decades of breathing in air pollution in his beloved Tooting, the area of south London he had spent his whole life in.
“My dad had been a bus driver, and one of my earliest memories is sitting on the top deck of the 44 as he
