Warrington is the latest area to move into the top tier of Covid-19 measures as infection rates continue to rise.
Tier three restrictions came into force at midnight in the Cheshire town - two days earlier than originally planned.
Council leader Russ Bowden said it was the right decision to move Warrington into the "very high" Covid alert level.
"This is a public health imperative. What we need to do is protect the lives of our residents," he said.
"And - obviously alongside that - [it is about] protecting businesses and jobs here in the town".
He added that one of the main concerns was the "way the cases have propagated into the older working age population and particularly those people above 60".
Warrington, which is home to about 210,000 people, joins the Liverpool City Region, Lancashire, Greater Manchester and South Yorkshire in tier three.
Nottingham and parts of Nottinghamshire will move into the top tier from Thursday.
Health and Social Care Secretary Matt Hancock said the decision to move Warrington into tier three was agreed with local leaders as "it's time to take action" due to rising infection rates.
"Please remember - now is the time for us all to work together to get this virus under control," he said.
The new rules mean:
- Residents must not socialise with anyone outside their household or support bubble in any indoor setting - including homes and private gardens - or at most outdoor hospitality venues
- They must not socialise in a group of more than six in an outdoor public space, such as parks
- Pubs and bars that do not serve substantial meals as a restaurant must close
- Residents are advised to avoid travelling outside the area, unless for essential journeys, such as work or caring responsibilities
- Betting shops, adult gaming centres, casinos and soft play centres will also close
Mr Bowden told Radio 4's Today programme that cases remained "stubbornly high" and he was worried about "Covid fatigue" with people unable to see a way out of the tougher restrictions.
He said: "There are no clear rules about what the success criteria are with the tiers and how you move between the different tiered layers."
Mr Bowden added: "The vast majority of people have applied themselves to the rules and we are asking people again to step up and take responsibility for their actions to protect their loved ones. "
Analysis - Rob England, BBC Data Unit
Placed between Greater Manchester and the Liverpool City Region, Warrington currently has an infection rate similar to areas on the lower end of tier three, but it is rising.
The latest government figures to the 23 October suggest 399 people for every 100,000 had Covid, not far off double the rate seen a month ago and the 36th highest rate of England's 315 local authorities.
Geographically, its infection rate is closer to areas like St Helens to the north-west (437 per 100,000) and Trafford to the east (428 per 100,000) rather than other parts of Cheshire, where the rate is around 200 per 100,000.
Since the start of the pandemic Warrington has seen 189 deaths due to coronavirus, with 14 of those in the week to the 23 October. As it stands, only 19 other authorities saw more deaths over the same period.
Communities Secretary Robert Jenrick has confirmed the tier three measures for Warrington will be reviewed in 28 days' time.
"The restrictions we have agreed together will only be in place for as long as they are absolutely necessary," he said.
As part of the tier three move, the council has received a £5.9m support package from the government, incorporating £1.68m for public health and £4.2m for business and employment support.
The Lower Angel pub in Warrington town centre will be forced to close under the tightened measures.
Landlord Andrew Wharfe, who has worked there for 13 years, said he has never seen it so quiet.
"We're not big enough to serve food so we have to shut," he said, adding it had been an upsetting time.
Mr Wharfe said he had been planning to step down from the job next year - a decision he made before the pandemic - but this was now uncertain.
"This has put a nail in the coffin - we have had enough," he said.
Pauline Mellor, 56, who lives in Warrington, said: "My first grandchild was born in July and it is killing me not being able to see him."
She said she knew the rules but believed "they won't work".
"I work in a supermarket, and so many customers, even with a mask, come up close to you.
"I know we can meet outdoors in tier three but it is too cold - especially for a three-month-old baby," she added.