Video report by ITV News Political Correspondent Libby Weiner
A new fine of £800 is being introduced for people caught at house parties, Home Secretary Priti Patel has announced.
At a Downing Street press conference, she said from next week police will be able to give out on the spot fines to anyone at an illegal gathering of more than 15 people.
Fines will double for each repeated offence, with officers able to give out a maximum penalty of £6,400.
Officers can already hand out £10,000 on the spot fines to organisers of illegal gatherings.
"The science is clear: such irresponsible behaviour poses a significant threat to public health," Ms Patel said, "not only to those in attendance but to our wonderful police officers who attend these events to shut them down."
Pointing to the new 1,290 coronavirus deaths reported on Thursday, Ms Patel said breaches of lockdown rules were "costing lives".
Chair of the National Police Chiefs’ Council, Martin Hewitt welcomed the new fines, labelling house parties as "dangerous, irresponsible and totally unacceptable".
He said officers will not "waste time" trying to reason with people breaking the rules in such a way.
He said: "When we see people that are putting themselves and others in danger, we will not waste time trying to reason with them.
"They are demonstrating no regard for the safety of others, or even for themselves."
The current fine for people caught at house parties is £200 - £100 if paid early.
The Home Office said police will "continue to engage with the public, explain the rules and encourage compliance, but for egregious breaches such as parties, offenders can expect to receive a fine if they break the rules".
He cited several examples of flagrant rule breaches, in particular one illegal gathering in London with 40 people in attendance.
Three officers were injured while breaking up the party, with one requiring hospital treatment.
Last week, South Yorkshire Police issued 127 Fixed Penalty Notices, of which 92 were for indoor gatherings.
At the weekend, 15 people were fined at a house party at a holiday rental in Sheffield.
In Greater Manchester, police responded to three separate parties over the weekend, the largest one involving more than 40 people at a flat in Cheetham Hill.
The Metropolitan Police issued more than 140 fixed penalty notices totaling £39,000 in just two days last weekend.
The home secretary, asked whether tougher restrictions would be brought in to bring down coronavirus levels in England, said it is "too early to even speak about other measures".
She was being asked the question after Northern Ireland announced its lockdown was being extended until at least March 5.
Ms Patel said: "With regards to lockdown measures, you've heard the numbers today, we're in the midst of a global pandemic.
"It's too early to even speak about other measures."
Earlier Boris Johnson refused to put a timetable on when England's lockdown might end.
The prime minister, on a visit to flood-hit Didsbury, in south Manchester, warned the new Covid-19 strain is "much more contagious" than older variants, refusing to give a timescale as to when restrictions might end.
Acknowledging the findings of a survey which found infections may have gone up at the beginning of the current lockdown, Mr Johnson urged people to "obey the current restrictions "in what is unquestionably going to be a tough few weeks ahead".
Asked whether it will be spring or summer, Mr Johnson said: "I think it's too early to say when we'll be able to lift some of the restrictions."
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Also at the press conference Ms Patel urged everyone in the UK to accept a coronavirus vaccine if offered one, insisting jabs are is "safe for us all" and it's the UK's "best chance of beating this virus".
She was addressing vaccine disinformation, particularly that targeted at individuals from ethnic minority backgrounds.
She told the Downing Street press conference: "I want to take this moment and opportunity to counter some of the disinformation about the vaccine especially any messages targeted towards those from an ethnic minority background.
"So I urge everyone from across our wonderfully diverse country to get the vaccine when their turn comes to keep us all safe."
Watch the press conference in full: