British Prime Minister Boris Johnson has urged people to "act responsibly" when pubs in England reopen on Saturday after more than three months of coronavirus lockdown -- and revealed he himself plans a visit.

The 56-year-old, known for his unruly blond hair, has also booked in at the hairdresser after they too reopen in England at the weekend alongside libraries, museums, cinemas, restaurants and hotels.

Johnson said the easing of restrictions "is about supporting the livelihoods of business owners and their employees", who he said had put in a "heroic effort" to make their venues safe.

"But the success of these businesses, the livelihoods of those who rely on them, and ultimately the economic health of the whole country is dependent on every single one of us acting responsibly," he said. 

"We must not let them down.... Because we are not out of the woods yet."

The spike in cases in the English city of Leicester, which led to local schools and shops this week being shut again and the July 4 reopenings delayed, was proof that "the virus is still with us".

"If it starts running out of control again the government will not hesitate in putting on the brakes and re-imposing restrictions," Johnson said in a statement.

"So as we take this next step, our biggest step yet, on the road to recovery, I urge the British public to do so safely."

In an interview with London's Evening Standard, Johnson revealed he planned his own trip to the pub, and "I will be having a haircut as soon as I can. It's booked".

Britain has suffered the deadliest outbreak of COVID-19 in Europe, recording around 44,000 deaths among patients who tested positive, rising to over 54,000 if suspected cases are included.

Some experts have warned that Johnson, mindful of the economic havoc brought on by the lockdown, is moving too quickly in reopening the hospitality industry.

The devolved administration in Northern Ireland is opening indoor venues on Friday but Scotland is holding off until July 15. Wales has not set a date yet.