New rules in force for three UK nations

Mr Johnson, who suffered the largest rebellion since he became prime minister when MPs voted on his Plan B measures earlier this month, said before Christmas that he “can’t rule out” further measures after the holiday.

Since then, preliminary findings by the UK Health Security Agency have found the Omicron variant may be less likely to cause serious illness than the previously dominant variant, Delta.

Leading Tory backbench MP Sir Graham Brady said “enough is enough” and welcomed reports that ministers were resisting any further restrictions.

Writing in the Mail on Sunday, he said: “Even with new concrete evidence that the Omicron variant will not cause the devastation first predicted, there are very real fears that, if this year’s Christmas has been reprieved, New Year could be cancelled instead. It must not happen.”

The UK government is continuing its strategy of encouraging the take-up of booster vaccines to protect against the Omicron variant, sending out millions of text messages on Boxing Day urging people to “get boosted now”.