The latest phase in a gradual reopening of the British economy on Saturday will see pubs in England open their doors for the first time since mid-March, as well as the reopening of restaurants, museums, hotels and other businesses.

The much-awaited event has been dubbed "Super Saturday" in the media, sparking worries that after months cooped up indoors, some could get carried away and risk spreading COVID-19.

"Ultimately the economic health of the whole country is dependent on every single one of us acting responsibly," Johnson is expected to say at a news conference on Friday.

Many of the elements that define a pub will be missing when they reopen: with numbers limited, there will be no crowds, no standing at the bar and no live music. Venues will have to keep a record of customers in case of a virus outbreak.

Johnson has previously said he is looking forward to visiting a pub himself but has warned patrons will have to stick to new rules.

He is expected to repeat that caution on Friday, pointing to a spike in cases that has forced the English city of Leicester to be locked down. Johnson will warn that freedoms could be swiftly revoked if the virus takes hold elsewhere.

Asked if Johnson would be visiting a pub or restaurant on Saturday, the spokesman said: "He's talked about his enthusiasm for a haircut and pint previously but I don't know exactly what he's doing on Saturday yet."

The prime minister's warning comes as the government says it will lift its COVID-19 quarantine requirement for people arriving in England from countries including Germany, France, Spain and Italy from July 10.

A full list of countries covered by the relaxation will be announced on Friday, the country's transport ministry says.

Under the existing rules, travellers must self-isolate for 14 days on entering the country, something airlines and the travel industry have said will cost thousands of jobs and inflict further damage on the economy.

Australian Associated Press