Boris Johnson is taking a gamble with his decision to stick with the easing of Covid restrictions for Christmas. The gamble is that people will suddenly start adhering to government guidance and severely restrict their contact with their families, even though the law does not force them to do so. Although, as the Prime Minister argued at this afternoon’s press conference, the government’s current level of involvement in people’s lives is probably the strictest since Cromwell, it remains the case that it has repeatedly concluded this year that it has to force people to restrict their social contact, rather than ask them – whether that’s nicely or in the current special stern voice that ministers have decided to adopt.

Johnson’s special stern voice today involved him testing out various Christmas slogans and puns, telling people that: ‘A smaller Christmas is going to be a safer Christmas, and a shorter Christmas is a safer Christmas.’ Later in his statement, he said: ‘So have yourself a merry little Christmas, and I’m afraid this year I do mean little.’

He was backed up in his argument by chief medical officer Professor Chris Whitty, who told the Downing Street briefing that just because people could do something, it didn’t mean that they should. He warned that the modelling showed more mixing at Christmas would lead to more deaths, but added that he didn’t think from conversations his medical colleagues were having with people across the country, that many people would push things to the limit anyway. He said that most would act responsibly, as they had done throughout this crisis.

This is once again a gamble. Even though opinion polls suggest that the majority of people think the government’s Christmas restrictions are too lax, it is not clear if they really think they are too lax for other people and that their own arrangements don’t count because they only represent a small and justifiable infringement of the guidance.

One of the features of this pandemic has been a willingness from some quarters to judge other people doing exactly the same activity you are, such as taking disapproving photos of groups enjoying the sunshine in the park – while in the park yourself. What matters to the efforts to drive down social contact is not one’s ability to look down on others, but the decisions each person takes themselves. Johnson and Whitty are clearly hoping that their comments today will increase peer pressure on people to cut down on their Christmas activity. But with the four nations increasingly diverging from the ‘unanimous agreement’ they apparently reached this afternoon about Christmas, it will be very easy to see whose approach ended up being the most effective in the weeks after the festive season.