The UK could be put into another full lockdown before Christmas if new coronavirus restrictions are not followed, the foreign secretary has suggested.
Dominic Raab said Britain could "get through" winter without a return to a national lockdown if "everyone plays by the rules", but warned "more intrusive" measures could soon be implemented if Covid-19 infections continue to surge.
His warning follows a plea from Prime Minister Boris Johnson who urged Britons to "summon the discipline, and the resolve, and the spirit of togetherness that will carry us through".
On Tuesday's News At Ten, Political Editor Robert Peston reported on the new restrictions shortly after Boris Johnson's announcement
In a televised speech, the first of its kind since the first lockdown was announced in March, Mr Johnson said Britain will "get through this winter together" if new coronavirus restrictions are followed.
New rules in England include a 10pm curfew for pubs, a tightening of the rule of six and fresh advice for people to return to working from home.
Foreign Secretary Raab said a second national lockdown could be needed to control the spread of coronavirus if the latest measures do not work.
"We can avoid having to go even further with further measures or indeed a national lockdown, which is the risk if we don't take action now," he told ITV News.
He told Sky News: "We've always said we've got a sort of repository of measures in the arsenal to take. I don't think we would speculate about what further could be done.
"But the reality is they will be more intrusive or we could end up in a national lockdown. That is what we want to avoid."
He added: "Let's hope that we can get through the winter months if we take these measures and if everyone plays by the rules, and we go into Christmas not needing to go into that national lockdown with all the impact on society and families but also the damage it would do to businesses."
Mr Raab told the BBC that a "small minority" could "blow it for everyone else" if they do not obey the new rules.
Raab: 'There's no silver bullet...'
He said: "The risk is, of course, that that frays at the edges, that a small minority, if I can put it this way, blow it for everyone else, and that's why the measures that we've introduced are targeted along with increased fines and making sure we've got consistent enforcement and compliance."
Prime Minister Johnson, in his speech to the nation, warned of some "unquestionably difficult months" ahead in UK's fight against Covid-19, but said "things will be far better by the spring" if people stick to the new guidance.
"But if people don’t follow the rules we have set out, then we must reserve the right to go further," Mr Johnson said, adding: "If we were forced into a new national lockdown, that would threaten not just jobs and livelihoods but the loving human contact on which we all depend."
"Unless we take action the risk is that we will have to go for tougher measures later, when the deaths have already mounted and we have a huge caseload of infection such as we had in the spring," he said.
The prime minister warned that coronavirus is "no less fatal than it was in the spring" as he urged people to consider the vulnerability of other people.
"These risks are not our own," he said. "The tragic reality of having Covid is that your mild cough can be someone else’s death knell".
Watch Boris Johnson's lockdown speech in full:
Despite warnings that "hospital admissions are climbing", the prime minister attempted to strike an optimistic tone in his statement.
"Things will be far better by the spring when we have not only the hope of a vaccine, but one day soon – and I must stress that we are not there yet - of mass testing so efficient that people will be able to be tested in minutes so they can do more of the things they love.
"That’s the hope; that’s the dream. It’s hard, but it’s attainable, and we are working as hard as we can to get there."
He added: "The fight against Covid is by no means over. I have no doubt, however, that there are great days ahead."
The new coronavirus restrictions explained:
Earlier, Mr Johnson told MPs that new restrictions in England - which include a curfew on pubs and a tightening of the 'rule of six' - are likely to be in place for six months.
In his statement to the nation, Mr Johnson thanked the majority of the public for following the guidance, but said "there have been too many breaches – too many opportunities for our invisible enemy to slip through undetected".
He warned: "For that minority who may continue to flout the rules, we will enforce those rules with tougher penalties and fines of up to £10,000."
Rule changes for England were first announced by the prime minister in the House of Commons earlier on Tuesday and many of the new restrictions have been adopted by the other UK nations.
Mr Johnson said the new rules are likely to be in place for six months unless they result in a swift decline in virus infections.
Changes in England:
People now advised to work from home if possible
Hospitality ordered by law to close at 10pm
Rule of six extended to indoor sport, meaning, for example, indoor five-a-side banned
Weddings attendances are restricted to a maximum of 15
Planned return of fans to events such as football matches cancelled
Face covering laws extended to both staff and customers in retail, hospitality
Fines for rule breaches doubled to £200
Restrictions on businesses come into force on Thursday, working from home advice is effective immediately and rule changes on weddings and face coverings should be followed from Monday.
The prime minister held a Cobra meeting with the first ministers of Scotland, Wales and Northern Ireland before announcing the new measures for England.
All leaders "agreed on the need to work on a four-nation basis to discuss UK-wide measures where these were necessary".
Varying measures are being imposed in all four UK nations, with Scotland choosing to go furthest in a tightening of restrictions there.
On top of curfew restrictions, which will be enforced from Friday, Scots have been told that gatherings between households are banned as of Wednesday.
The same rule came in to force in Northern Ireland on Monday.
Nicola Sturgeon accepted that the latest coronavirus restrictions may feel like a "step backwards", but urged Scots to stick with them anyway, insisting they "will make a difference".
Nicola Sturgeon announces the new rules in Scotland:
Wales has also adopted the restrictions on businesses, but is also advising its citizens to avoid all but essential travel.
There's also a ban on alcohol sales in Wales after 10pm.
First Minister Mark Drakeford confirmed the measures as part of a televised address on Tuesday evening.
"In the weeks and months ahead of us, there is a very real possibility that we could see the virus regain a foothold in our local communities, towns and cities," Mr Drakeford said.
"Now none of us wants to see that happen again. 2020 has been an incredibly difficult year. We have all sacrificed so much. "
He added: "Families have lost loved ones. People have lost jobs and livelihoods. This is a highly infectious virus. We cannot let it take a hold of our lives again. We have come too far to let that happen."
Mark Drakeford announces new rules in Wales:
In Northern Ireland households will no longer be allowed to mix indoors and no more than six people from two households can meet outdoors, but businesses will be unrestricted.
Northern Ireland's First Minister said the virus had "crept into communities" in every county in the region.
Arlene Foster said: "We need to act but I do want to reassure you that despite all of the headlines this is not a second lockdown, this is a wake-up call, a reminder that we are not out of the woods. "
She added: "We have agreed that your school, your shop, your factory, your business, your college, your local hotel or restaurant will remain open because they have all taken steps to stop the spread of the virus."
The administration in Northern Ireland has been criticised for allowing wet pubs - venues that only serve drinks - to reopen on Wednesday.
Deputy First Minister Michelle O'Neill acknowledged it sends a "confusing message", but said "the pub sector is the only part of the whole entire hospitality sector that hasn't opened, so I think you have to be reasonable about all that".