A No 10 source says he remains “in contact” with the rest of the team.
Last week he was spotted running out of Downing Street just hours after his boss, the PM, had been diagnosed with the illness.
Aides said he was just late for a meeting.
Boris Johnson and Matt Hancock, the Health Secretary, both tested positive for coronavirus last Friday, sparking panic in Government about who else could be infected.
The Government’s Chief Medical Officer, Chris Whitty, is also isolating at home with symptoms.
It’s not clear whether he has had a test.
Scottish Secretary Alistair Jack this weekend became the latest member of the Government to say they would be staying home after feeling unwell.
