Lancashire has agreed to move into tier three - the top level of England Covid restrictions - from Saturday.
The "very high" alert level measures include pub closures and bans on household mixing indoors, in private gardens and most outdoor venues.
However, gyms and leisure centres would not close, unlike in Liverpool City Region - the other area in tier three.
Some local council leaders said they had been "bullied" into accepting the deal by Downing Street.
However, Health Secretary Matt Hancock said the government had "worked intensively with local leaders" to agree the move.
He added that an "unrelenting rise in cases" in the north-west England county had meant "we must act now".
Around 1.5 million people, including those living in Blackburn, Blackpool, Burnley, Lancaster and Preston, will be affected by the new rules.
The Labour leaders of Preston, Pendle and South Ribble councils released statements saying they had been forced to accept a deal that would not be enough to stop the virus.
Paul Foster, of South Ribble said: "We have been bullied, harassed, threatened and blackmailed into moving into tier three."
He added: "The discussions with government were a complete shambles and we were basically told if we didn't accept the restrictions we would have even more draconian measures imposed on us."
However, Geoff Driver, the Conservative leader of Lancashire County Council, told the BBC: "It's been a long drawn out process but I think we've got a good deal."
He said it involved a support package worth £42m, the area having initially been promised £12m, with £30m to help the businesses affected.
Mr Driver said Lancashire had also been promised more support for local test and trace and a specific ministerial team to deal with the outbreak in the county.
"What we've been able to do is to convince government that the measures we have in place to monitor such things as the gyms and the leisure centres are sufficient to ensure that they're not a source of infection," he added.
The new measures, which will be reviewed every two weeks, cover all parts of Lancashire:
- People must not socialise with anybody they do not live with, or have formed a support bubble with, in any indoor setting or in any private garden or at most outdoor hospitality venues and ticketed events
- People from different households can still meet in an outdoor public space such as a park or beach, the countryside, a public garden or a sports venue, in groups of six or less
- All pubs and bars must close, unless they are serving substantial meals
- Residents should avoid staying overnight in another part of the UK, and others should avoid staying overnight in the area
- People should try to avoid travelling outside the very high alert level area or entering the very high alert level area, other than for essential journeys or to travel through as part of a longer journey
- From Monday 19 October, casinos, bingo halls, bookmakers and betting shops and soft play areas must close and car boot sale will not be permitted
Further restrictions may be agreed for particular regions in the top tier and in the Liverpool City Region, gyms and leisure centres have also been forced to close.
Measures 'inconsistent mess'
Mayor of Liverpool Joe Anderson tweeted: "Liverpool City Region has demanded immediate clarification on why Lancashire gyms are allowed to stay open and Liverpool's close.
"Inconsistent mess - we now have tier three A and tier three B."
Steve Rotheram, the mayor of the Liverpool City Region, said he was "concerned that there appear to be differences between the two packages of measures, particularly the opening of gyms".
"We have always been clear that we were given no choice about the specific package of measures that would be applied to us," he said.
However, the prime minister's official spokesman said it was up to regional leaders to decide whether gyms should be closed.
"The purpose of the very high level is to allow for local, tailored interventions and they are determined on the basis of discussions with local authorities and based on local evidence," he said.
It comes as talks between Greater Manchester leaders and central government over putting the region into tier three of England's three-tier system have stalled.
Greater Manchester's mayor Andy Burnham wants more financial support for people affected before bringing in tougher rules.
Foreign Secretary Dominic Raab accused Mr Burnham of "effectively trying to hold the government over a barrel over money and politics".
On Thursday, London, Essex, York and parts of Surrey, Derbyshire and Cumbria were moved up to tier two and will face tougher measures from Saturday.
More than half of England's population will now be living under high or very high-alert restrictions.
Meanwhile, First Minister Mark Drakeford said Wales was facing a two-week national lockdown, calling it a "fire break".
He said a decision was likely to be made on Monday, with discussions continuing with health officials, scientific advisors and councils over the weekend.
It comes as a ban on travelling to Wales from coronavirus hotspots elsewhere in the UK comes into effect on Friday evening.
In Northern Ireland, pubs, restaurants and cafes will only be allowed to offer takeaway and delivery services for four weeks from 18:00 BST on Friday.
Tighter rules around face coverings have come into effect in Scotland, making them mandatory in workplace setting such as canteens.
In other developments:
- Coronavirus infections are continuing to rise rapidly in England, with an estimated 27,900 new cases a day, according to the Office for National Statistics
- Pret a Manger and Edinburgh Woollen Mills have announced a further 1,000 job cuts.
- A study from the World Health Organization has found anti-viral drug remdesivir, recently given to US President Donald Trump, has little to no effect on Covid patients' chances of survival
On Thursday, a further 18,980 cases and 138 deaths within 28 days of a positive test were reported across the UK.
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