A PLANNED easing of England's lockdown has been postponed a day before it was due to come into effect, as the Prime Minister warned the country "cannot be complacent" amid a rise in the prevalence of coronavirus in the community.

Measures due to be lifted on Saturday, including allowing small wedding receptions and re-opening bowling alleys and casinos, have been delayed for at least two weeks.

And in a strengthening of precautions, Boris Johnson announced that face coverings will become mandatory in indoor settings such as museums, galleries, cinemas and places of worship from August 8.

READ MORE: Scots told to avoid parts of northern England after Covid-19 spike

In a Downing Street press conference on Friday, the Prime Minister revealed what he described as a "pretty punchy" new slogan - "Hands, face, space" - for people to be mindful of in their efforts to control the spread of Covid-19.

England's chief medical officer, Professor Chris Whitty (below), warned that it might not be possible to ease lockdown further, saying the UK has "probably reached near the limit or the limits" of what can be done to re-open society.

The National:

Friday's news came after local lockdown measures were announced in parts of the North West of England and areas of West Yorkshire, banning people from different households meeting indoors or in gardens following a spike in virus cases.

Johnson told the briefing: "As we see these rises around the world, we can't fool ourselves that we are exempt. We must be willing to react to the first signs of trouble."

He added: "We cannot be complacent and I won't stand by and allow this virus to threaten to cause more pain and more heartache in our country."

He said that, with numbers rising, "our assessment is that we should squeeze that brake pedal in order to keep the virus under control".

The Office for National Statistics said there has been an increase in the number of people testing positive for coronavirus in England, with Johnson saying the prevalence of the virus in the community is likely to be rising for the first time since May.

According to the ONS, between July 20 and 26 there were around 0.78 new Covid-19 infections for every 10,000 people in the community population in England - equal to around 4200 new cases per day.

READ MORE: BBC slammed for portraying Rishi Sunak as Superman

This is up from an estimated 2800 new cases a day in the previous week.

Data released on Friday also showed the R value for the UK is between 0.8 to 0.9, a slight change from 0.7 to 0.9.

On Thursday evening it was announced that people from different households in Greater Manchester, parts of east Lancashire and West Yorkshire would no longer be allowed to meet each other inside their homes or in gardens.

The new rules, which came into effect from midnight, also ban members of two different households from mixing in pubs, restaurants and other hospitality venues, but these businesses will remain open for those visiting individually or from the same household.

Whitty told the briefing: "I think what we're seeing from the data from ONS and other data is that we have probably reached near the limit or the limits of what we can do in terms of opening up society.

"So what that means potentially is that, if we wish to do more things in the future, we may have to do less of some other things.

"And these will be difficult trade-offs, some of which will be decisions for Government and some of which are for all of us as citizens to do.

"But we have to be realistic about this. The idea that we can open up everything and keep the virus under control is clearly wrong."

Despite the delay to the Government's road map on re-opening, Johnson said he encouraged people "to think of wonderful staycations here in the UK".

Other re-openings which will not take place as planned across England on Saturday include indoor performances, pilots of larger gatherings in sports venues and conference centres, and close-contact services such as facials and make-up application.

READ MORE: Sky News host claims Scotland would have 'gone bust' without England

Johnson said that, while most people are following the rules, there will be a "greater police presence" to ensure the public is adhering to the requirements around face coverings and stressed that local authorities can close down premises and cancel events which are not following the guidance.

Shielding advice will still be paused as planned on Saturday and guidance around allowing more discretion for employers with regard to staff returning to work will also go ahead, the Prime Minister said.

Accepting that Friday's announcement would be a "real blow" to people who had wedding plans or those who can no longer celebrate Eid as they had hoped, Johnson said "we simply cannot take the risk" but vowed to open up more fully "as soon as we possibly can".