Emily Ashton And Kitty Donaldson Bloomberg

In a Downing Street office last week, under the glare of chandeliers and a big television screen, a flash of frustration burst across Rishi Sunak's face during a conference call.

Boris Johnson warned of serious challenges ahead in tackling the omicron Covid-19 variant, as he eased testing rules to free up capacity to cope with a virus caseload that's surging across the U.K.

In a Downing Street office last week, under the glare of chandeliers and a big television screen, a flash of frustration burst across Rishi Sunak's face during a conference call.

Boris Johnson warned of serious challenges ahead in tackling the omicron Covid-19 variant, as he eased testing rules to free up capacity to cope with a virus caseload that's surging across the U.K.