Boris Johnson has been forced to quarantine after a Tory MP he had a meeting with on Thursday tested positive for coronavirus.
The Prime Minister says he was informed on Sunday that he would have to self-isolate after Lee Anderson contracted the virus.
"I have no symptoms but am following the rules and will be working from No10 as I continue to lead the government's pandemic response," he said.
Mr Anderson uploaded a picture of him and the Prime Minister to Facebook, in which neither of them is wearing a face mask and they seem to be less than 2 metres apart.
Tory MP, Lee Anderson said on Facebook that he lost his sense of taste on Friday, had a test on Saturday and was confirmed positive on Sunday.
Mr Johnson was hospitalised in March after testing positive for coronavirus and spent three nights in intensive care.