Mark Sedwill: PM’s trusted adviser with key role in Gavin Williamson sacking

Mark Sedwill leaves parliament in 2014 in London. Photograph: Peter Macdiarmid/Getty ImagesGrammar-school educated, like Theresa May and a number of her closest confidantes, Mark Sedwill is a career civil servant, who has worked closely with the prime minister since she was home secretary.His appointment to the job of cabinet secretary began as a temporary one, after Lord Jeremy Heywood stepped down to receive treatment for cancer.After Heywood retired, shortly before his untimely death, Sedwill