British Prime Minister Boris Johnson on Monday said he was in "good health" and had no COVID-19 symptoms ahead of his self-isolation.

Earlier in the day, Britain's National Health Service (NHS) Test and Trace had notified the prime minister that he must self-isolate, as Conservative MP Lee Anderson, who Johnson met on Thursday, tested positive for the virus.

In a video released on Twitter, Johnson said he would lead the virus response from his Downing Street home.

The news comes seven months after Johnson tested positive for the novel coronavirus in April and spent three days in intensive care.

The British leader had been hoping to seize back the initiative after last week's drama in Downing Street.

Johnson's office said on Friday that Dominic Cummings, the prime minister's most powerful adviser and a fellow veteran of the Brexit referendum, will stop working for him next month.

Negotiations with Brussels over a post-Brexit trade deal with the European Union are reaching a climax ahead of the December 31 expiry of Britain's transition period. 

Johnson also has to decide his next move on England's coronavirus restrictions after he ordered a four-week lockdown that is due to end on December 2.

(With inputs from Reuters)