Keir Starmer is self-isolating after a member of his household showed symptoms of coronavirus.
A spokesperson for the Labour leader said the family member has had a test and that Starmer is following guidance by self-isolating until results arrive.
Starmer was alerted to the news just after finishing a session of Call Keir on LBC radio on Monday morning.
He has not shown any symptoms of the disease and will be working from home, the spokesperson added.
They said: “This morning Keir Starmer was advised to self isolate after a member of his household showed possible symptoms of the coronavirus.
“The member of his household has now had a test. In line with NHS guidelines, Keir will self-isolate while awaiting the results of the test and further advice from medical professionals.”
The prime minister’s official spokesman said that Boris Johnson has spoken with Starmer on Monday morning and offered him his best wishes.
Starmer had been due to speak in the Commons in a debate on the government’s controversial internal markets bill.
Five former prime ministers have spoken out about the legislation, which effectively breaks international law because it unpicks parts of the Withdrawal Agreement (WA) negotiated by Boris Johnson last year and gives UK ministers key powers to decide when EU rules apply to Northern Ireland.