Nothing will be decided in a formal sense until all four nations of the United Kingdom are as one. And the decision is slightly harder because Northern Ireland's leadership wants a Christmas consensus with Dublin.
But it is looking highly probable that all four UK governments’ special Christmas exemption from coronavirus restrictions will allow us to socialise with people from two households in addition to our own household over five days beginning on 23 December and ending on 27 December.
Or to put it another way, for those five days, a typical family will be able to enjoy festive meals indoors with both sets of grandparents, or two groups of friends, or whomever is most special to them.
Which may be a pleasant surprise for some, though the decision on precisely who to include in our Christmas bubbles may be fraught and stressful for many of us.
This Christmas easing of Covid-19 restrictions will be announced by the PM to MPs on Monday afternoon, along with the detail of the new tiered restrictions to which we'll return when our four-week lockdown ends on 2nd December.
Each region will again be placed in one of three tiers. And the most important changes to the tiers will be these:
1) Tier 3 will be toughened, in that hospitality will remain closed (the previous Tier 3 rules allowed pubs and restaurants to open to serve proper meals to single households and for business meetings);
2) where hospitality is allowed to open, in Tiers 1 and 2, last orders will be at 10pm but people will be permitted to stay in pubs and restaurants till 11pm, to avoid crowds and crushes on the way out.
In all three tiers, non-essential shops will re-open, hairdressers and personal care services will reopen, gyms will re-open, and outdoor sports will resume.
There will be an announcement to parliament on Thursday about which regions will be in which tiers.
These difficult decisions will be made on the basis of the latest Office for National Statistics survey data on local prevalence of the virus and infection rates, plus data on hospital admissions and usage of intensive care units.
Early next week, probably Monday, MPs will have the opportunity to debate and vote on all this.
Finally there are two other big changes being announced tomorrow.
First is that any local authority that is put into Tier 3 can ask the government for the kit and resources to test every single person in the area, to identify all of those who have the virus, including those with no symptoms, so that these asymptomatic people can be quarantined to drive down the spread of the virus.
This is a tool to help a Tier 3 area become a Tier 2 one rapidly.
And there will be a pilot in Liverpool that will allow those identified as being in contact with an infected person to take a lateral flow Covid-19 test every single day for a week, and if the test result is negative they will be able to go about their lives as normal for that day.
This would be an alternative to 14 days of isolation at home.
If the pilot is successful, it will be made available everywhere.
This expansion of testing means that the annual cost of NHS Test and Trace will rise from a staggering £15bn to an almost unbelievable £22bn.
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