State epidemiologist Anders Tegnell, the herd-immunity architect, expanded on the proposals for the capital after first signalling the shift on Tuesday.

‘We are thinking of fairly short restrictions, to break the spread of infection requires perhaps two to three weeks at most,’ Tegnell told the Dagens Nyheter newspaper on Wednesday. ‘We are still developing the concept, so to say, but something like that.’

Tegnell added: ‘The restrictions could be extremely local. It could be about a single workplace or city district: wherever you see a spread and think that there are restrictions that might stop it.’