UK Prime Minister Boris Johnson is not on a ventilator in intensive care but has received oxygen support, says Cabinet Office Minister Michael Gove.
Gove said Downing Street will inform the country if there is any change in the prime minister's condition.
"The teams at St Thomas' are some of the finest doctors in the country," Gove told BBC Radio 4.
"The doctors, nurses and other staff will be making appropriate medical decisions and have our full support."