People planning to celebrate the end of 2020 have been told to avoid parties because "Covid loves a crowd", amid warnings of extra policing to stop mass gatherings.

The government has launched a campaign urging people in England to "See in the New Year safely at home", with adverts running across radio, print media and out of home advertising.

The initiative by Public Health England reminds the public how easily coronavirus can spread.

It says that one in three people have no symptoms and that they "should act like they have the virus to avoid spreading it without realising".

The advertising reiterates people should not meet up with friends or family indoors, unless they are in the same household or support bubble, and they should avoid large gatherings of any kind.

Health Secretary Matt Hancock, said: "With our NHS under pressure we must all take personal responsibility this New Year's Eve and stay at home.

"I know how much we have all sacrificed this year and we cannot let up. Over 600,000 people have now been vaccinated and we are close to beating this virus.

"Now more than ever, we need to pull together to save lives and protect our NHS.

"If we continue to do our bit by staying at home, we can get through this together."

London's annual New Year's Eve firework display over the River Thames is cancelled this year and no public gatherings are allowed.

However, Big Ben, which has been largely silent since 2017 while its clock tower is restored, will sound 12 bongs at midnight.

The Metropolitan Police issued a warning to potential revellers to "celebrate the New Year in the comfort of their own homes, not the homes of family and friends".

Those who break the rules could face fines starting from £100 to potentially £10,000.

Commander Paul Brogden, who is leading this year's operation, said: "The public can expect to see officers deployed across the capital, supporting communities and focusing strongly on the few people intent on breaching and ignoring the guidance put in place to keep everyone safe.

"Officers will also be paying attention to parts of London that are experiencing the highest infection rates."

NHS England's medical director Professor Stephen Powis said that marking the New Year at home with just your nearest and dearest and within the rules would "reduce infections, relieve pressures on hospitals" and help to save lives.

"Covid loves a crowd," he said. "So please leave the parties for later in the year."

Huge swathes of England joined London in the strictest COVID-19 restrictions on Boxing Day, with a further 20 million plunging into Tier 4 restrictions on 31 December.

The new measures mean millions of people can only gather outside with one other person who is not in their household.

Nearly everyone in Scotland and Northern Ireland are also subject to the highest level of restrictions - which means large gatherings, even outside, will be banned.

For the first time in its history, Scotland's flagship Hogmanay event is moving online - where it will be headed by actor David Tennant.

First Minister Nicola Sturgeon said: "I take no pleasure in saying this but we should ring in 2021 in our own homes."

The prime minister also had similar concerns over New Year's Eve celebrations.

He said: "I must ask you to follow the rules where you live tomorrow night and see in the New Year safely at home.

"That means not meeting up with friends or family indoors, unless they're in the same household or support bubble, and avoiding large gatherings of any kind."

It comes as deputy chief medical officer Professor Jonathan Van-Tam said the NHS had yet to see the impact of household mixing over Christmas.

He said the situation in the UK is "precarious in many parts already" and urged the public to "play your part from bringing us back from this very dangerous situation".

"It is almost certainly true that the NHS has not yet seen the impact of the infections that will have occurred during mixing on Christmas Day and that is also unfortunately rather sobering," Prof Van-Tam said.

New Zealand is one of the first countries to ring in the New Year, with Auckland pushing ahead with its traditional celebration at the Sky Tower and Harbour Bridge landmarks.

A few hours later, Australia will celebrate the beginning of 2021 with a fireworks display, however, people are banned from gathering near to Sydney Harbour Bridge under Covid rules.