UK PM says he won't outlaw Christmas

After imposing the most onerous restrictions in the country's peacetime history, Johnson is now keen to avoid becoming the first leader since Oliver Cromwell in the 17th century to cancel Christmas, even though the UK has the sixth worst official COVID-19 death toll in the world.

Hours after pubs and restaurants were forced to close again in London to tackle a worsening outbreak, Johnson said plans to ease restrictions for five days from December 23 would go ahead.

"We don't want to criminalise people's long laid plans," he told parliament.

"By being sensible and cautious, not by imposing endless lockdowns or cancelling Christmas ... that is the way we will continue to work together to keep this virus under control, to defeat it and take the country forward."

Johnson's plans to relax restrictions for five days so three households can mix have been criticised by two influential medical journals and a number of health experts.

COVID-19 has battered the UK. The government's most conservative death toll measure is 64,908, second only to Italy in Europe, while government borrowing is set to hit a peacetime high of 394 billion pounds ($A705 billion) in 2020/21.

Medical views are divided and there is concern growing among cancer specialists, for example, that many cancers are going undiagnosed due to the public health focus on COVID-19.

One cabinet minister suggested people should make up their own minds about what precautions to take and said some may want to wait for Easter to gather with their family given the risk to the elderly and the vulnerable.

Housing Secretary Robert Jenrick said it was not for government to tell people exactly how to behave.

"Easter can be the new Christmas for some people," he said.

The leaders of Scotland and Wales, which set their own often-stricter rules, urged people to show restraint.

Wales has also toughened general restrictions further.

Australian Associated Press