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”.