Michael Gove will chair a COBRA meeting with devolved administrations later as discussions continue about Christmas rules, according to government sources.
Ministers are trying to agree a UK-wide approach to relaxing COVID-19 restrictions over the festive period with the leaders of Scotland, Wales and Northern Ireland.
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The talks are expected to get under way around 4pm.
Ministers are working on plans for three households and a five-day break, from Christmas Eve to 28 December, subject to agreement from the devolved governments.
Scotland First Minister Nicola Sturgeon said on Monday that “we’re making progress towards a common position across the UK” on an easing of restrictions around Christmas, with it “likely [that] some households may be able to form slightly larger bubbles with each other for a short period”.
Welsh Health Minister Vaughan Gething, meanwhile, said the four nations were discussing “the potential for a limited period of time to have some relaxation” of the rules.
If an agreement is reached, Boris Johnson is expected to set out how families might be able to gather over Christmas later this week.
Speaking via videolink at a Downing Street news conference on Monday, the prime minister said Christmas will be “different” than in previous years, declaring: “Tis the season to be jolly, but also the season to be jolly careful.”
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Mr Johnson added: “We want to make sure we have a solution for Christmas that everybody can share understand and respect throughout the whole of the UK.”
Addressing MPs in the Commons earlier that day, the PM said families would have to make a “careful judgment” about visiting elderly relatives.
He said COVID-19 is “obviously not going to grant a Christmas truce” and warned that if people “blow it with a big blowout Christmas”, the country will pay for it with tougher restrictions heading into 2021.