7,563 recently retired clinicians had so far “answered the call” to return to work to help with the emergency.

Britain is also looking for 250,000 “NHS volunteers” to help national health service employees

There are multiple sections aimed at reducing the pressure on other frontline sectors, for example by relaxing rules around detention under mental health laws and increasing the use of audio and video links in courts.

Organisations could be required to provide space or resources for the storage or management of dead bodies, while rules relating to investigatory powers will be relaxed while the law is in force.

To support businesses, the bill will allow employers to reclaim statutory sick pay funds from HMRC to help with the burden of increased staff absence. For workers, it will scrap the three-day waiting period so that they can receive the payments from the day they stop working.

Mr Hancock said people whose jobs has not already been shut down by the government measures to date should continue to work but should only be travelling to a workplace “where that work can’t be done at home”.

He said construction workers – many of whom work outdoors – could and should continue to go to work as long as they are able to remain two metres apart at all times.

Self-employed workers may have to rely on the benefits system as things stand. Chancellor Rishi Sunak announced increased benefits for the self-employed, but did not guarantee their wages.

Police chiefs said phone lines were inundated with calls after the prime minister’s statement, as people rang to ask what they were still allowed to do.

The punishment in England for not complying would be a fixed penalty notice initially set at £30 for people breaking the rule of no public gatherings of three people or more

Prisoners in England and Wales will be confined to their cells for 23 hours a day and allowed out only to shower and use pay-phones, with all visits cancelled, the BBC understands.

The number of UK deaths rose to 422 on Tuesday, a rise of 87 in one day. 514 more people die in Spain, the worst day yet in the country. Italy has just reported a jump of 743 deaths in the past day – 141 more than Monday

Confirmed cases worldwide approach 400,000, deaths near 17,000, more than 100,000 recoveries