The WhatsApp group, called ‘PM Updates’, contained Boris Johnson’s closest advisers and discussions within the group touched on key Covid policies – such as shielding the clinically vulnerable, and the Department of Health and Social Care’s plans for responding to the pandemic.

But as plans for the inquiry took shape, Martin Reynolds – Johnson’s principal private secretary at the time – set the group so that messages sent would vanish after a period of time. It means potentially key discussions that took place are unavailable as evidence.