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 at the start of August, including allowing small wedding receptions, reopening bowling alleys and casinos and pilots of larger gatherings in sports venues, were delayed for at least two weeks.
And in a strengthening of precautions, Johnson announced new face covering rules that will come into force on 8 August.
What are the current rules?
People in England have to have their nose and mouth covered in shops and takeaway outlets or they could face fines of up to £100.
People using public transport must also wear face coverings, but this rule was in place before shops were included on 24 July.
Other indoor venues – including shopping centre, banks, railway and bus stations and airports – are also included in the rules.
What are the new rules?
From Saturday, the list of places where you will have to wear face coverings will grow.
The prime minister said that face masks would be “encouraged” at more indoor areas, but those places will now face the same restrictions as the existing ones.
Places where you will have to wear a face covering from Saturday are:
Places of worship
Cinemas and theatres
Museums and galleries
Libraries and public reading rooms
Public areas in hotels and hostels
Aquariums, indoor zoos or visitor farms
Tattoo and piercing parlours
Indoor entertainment venues
Nail, beauty, hair salons and barbers
Storage and distribution facilities
Premises providing professional, legal or financial services
What about exemptions?
Current exemptions to face coverings are the same. They are for those:
Under the age of 11
Not able to wear one due to a physical or mental illness, impairment or disability, or if wearing one will cause severe distress
Travelling with or providing assistance to someone who relies on lip reading to communicate
Avoiding harm or injury to yourself or others
Avoiding injury and don’t have a face covering with you
Eating or drinking if reasonably necessary
Asked by a police officer or other official to remove your face covering
What happens if you don’t wear one?
Anyone failing to wear a face covering in anywhere where one is required will be subject to the same penalties – a fine of up to £100, or £50 if paid within 14 days, with enforcement carried out by police and not retail staff.
Last month, it emerged that passengers who do not wear face coverings on public transport can have “reasonable force” used against them by police.
The Department for Transport rules can be enforced by police and transport staff with fines of £100.
The prime minister said last week that, while most people are following the rules, there will be a "greater police presence" to ensure the public is adhering to requirements around face coverings.