I'm fit as a butcher's dog: British PM Boris Johnson

British Prime Minister Boris Johnson has been self-isolating after someone he was in contact with tested positive for the coronavirus.

"It doesn't matter that I'm fit as a butcher's dog, feel great...that I've had the disease and I'm bursting with antibodies," he said in a video released on Twitter. 

"We've got to interrupt the spread of the disease and one of the ways we can do that now is by self-isolating for 14 days when contacted by Test and Trace," he added, saying he would lead the country's virus response from his Downing Street home.

Johnson spent three days in intensive care with coronavirus in April. This time around, Johnson said he was not suffering any symptoms and health minister Matt Hancock on Monday said he sounded "full of beans".

Johnson's self-isolation risks upsetting a busy week as the UK enters its third week of reimposed restrictions and the PM was due to chair a series of key Covid-19 meetings.

The prime minister was informed that he should self-isolate after being contacted by the country's Test and Trace scheme.

Johnson was hospitalised with the coronavirus in April. This time around, "the PM is well and does not have any symptoms of Covid-19", the spokesman said.

Johnson's confinement comes as negotiations with the European Union over Brexit enter a decisive final sprint. 

(With inputs from agencies)