Could we soon have coronavirus tests that are "simple, quick... and can turn round results in 90 or even 20 minutes"? That was the great hope expressed by Boris Johnson, as he described a "moonshot" plan for mass testing that would "in the near future" allow those who test negative to behave in a more normal way. It was the silver lining to a press conference during which the prime minister tightened restrictions on social gatherings in England - indoors or out - to six people.
However, scientists and health professionals are less optimistic that millions of such tests could be processed daily. "The mass-testing strategy is fundamentally flawed, in that it is being based on technology that does not, as yet, exist," says Dr David Strain, of the University of Exeter. Meanwhile, Dr Chaand Nagpaul, council chairman of the British Medical Association, points to both "huge problems" with lab capacity and a high rate of "false negatives" among those incubating the virus. According to medical journal the BMJ, which says it has seen a leaked government memo about the plan, carrying out up to 10 million tests a day by early next year would cost more than £100bn - approaching the entire annual budget for NHS England.
Revealing the new "rule of six" involved "quite the change of tone, change of pace, and change of heart" by a government that's spent weeks "trying to cheerlead the country back to the office", says our political editor Laura Kuenssberg. However, she says ministers are trying to "slam on the brakes" of a rapid rise in positive tests. The new rules only apply in England - remind yourself of the rules wherever you live via our explainer. And if you think you need a test, here's how to get one.

The UK will hold emergency talks with the EU later, over Boris Johnson's move to override key parts of last October's Brexit withdrawal agreement, notably the Northern Ireland Protocol. That aims to prevent peace being put at risk by the return of customs posts along the border with the Irish Republic, by having Northern Ireland continue to follow some EU customs rules. But a draft law published on Wednesday would give UK ministers powers to modify or "disapply" these rules, which will come into force on 1 January if the UK and EU cannot strike a trade deal.
The prime minister says the new law is required to "ensure the integrity of the UK internal market". However, his Northern Ireland secretary admits it would breach international law and our Europe editor Katya Adler says there's talk of legal action in Brussels, which views observation of the withdrawal agreement as a prerequisite to a trade deal. Meanwhile, the Democratic Speaker of the House of Representatives Nancy Pelosi says there is "absolutely no chance" of a US-UK trade agreement if the Northern Ireland peace process is jeopardised.

A frequent flyer tax... phasing out polluting SUVs... banning cars from city centres... These are just some of the ideas on tackling climate change set out in a 550-page report drawn up by a citizen's assembly of 108 people from all walks of life. The report demands the government show leadership on climate change and insists policies must be fair to all – especially the poorest in society. As our environment analyst Roger Harrabin sees it: "Its radical conclusions may offer political cover to ministers who’re typically nervous of a public backlash against policies that affect lifestyles." Find out more about the assembly and its ideas.

"There goes Christmas!" says the Daily Mail, in response to the UK government tightening restrictions on the number of people who can meet - indoors or out - in England. The cap of six people is likely to be in place "for six months", suggests the i. "Normal life is unlikely to resume before spring", says the Times. However, the Daily Express sounds a bit more optimistic, saying the festive season "can still be saved" if plans for mass testing for Covid-19 are brought in beforehand. Described by the prime minister as a "moonshot", it could cost £100bn, says the Guardian. It quotes a leaked memo seen by the British Medical Journal. That total, the Metro points out, is "almost as much as NHS England's entire £130bn annual budget". Read the review.

With English football's Premier League set to return at the weekend, read about the maths whizz who repurposed the modelling he uses for cancer research to top the official fantasy football league ahead of 7.6 million people. You might even pick up a tip or two. Or, if music's more your thing, hear from musicians, venues and labels about how they have adapted during the pandemic.

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