Mr Khan lives in Tooting, in Wandsworth, while Mr Bailey visited a vaccination centre in Wandsworth yesterday, where he had his first covid jab.
But their results will not come back quickly enough to allow them to enter the BBC building in central London that had been earmarked to host the 30-minute face-to-face debate on Eddie Nestor’s drivetime show on BBC Radio London.
BBC rules stipulate that anyone in a surge area – including the corporation’s own staff – is denied access until a negative PCR result is obtained.
BBC London radio chiefs decided to postpone the debate rather than attempt to do it via Zoom. A new date is being sought in the next fortnight.
BBC sources said no blame was attached to either candidate and that the BBC rules were designed to maximise its Covid security.
Anyone over 11 who lives, works or travels through Wandsworth or Lambeth is being asked to take a test. Residents in part of SE16 in Southwark are also being targeted.
Only the “gold standard” PCR tests can be used to detect the presence of Covid variants – meaning the rapid “lateral flow” tests cannot be used for surge testing. PCR results normally take about 24 hours to be received from a laboratory.
Mr Bailey was in Wandsworth’s neighbouring borough of Merton this morning, attending a Tamil celebration at a temple in Wimbledon.
Mr Khan is understood to be taking a PCR test today. He takes regular tests, normally two a week, both PCR and lateral flow.
A BBC spokesperson said: “Today’s debate has been postponed and will be rearranged.”