A programme of mass, instant coronavirus testing is to be rolled out to areas of England with the highest infection rates after lockdown is lifted next month, the prime minister has announced, as the government faces an unprecedented internal rebellion over Covid measures. Among the plans, which will rely on the ability to massively expand rapid testing systems across the country, is a scheme to stop people who have come into close contact with someone who has coronavirus from having to isolate for 14 days, if tests show they have not contracted it. Contacts will have the chance to be tested every day for a week, and will not need to isolate during that period if the tests remain negative. This would be trialled in Liverpool, and potentially rolled out nationally from January. Boris Johnson will on Monday outline plans for a tougher three-tiered set of restrictions to come into force once current measures lift on 2 December. He is also expected to unveil proposals for a temporary UK-wide relaxation to allow mixing between households over Christmas. It is understood that all the new tiers will allow nonessential shops and gyms to remain open. Rules for pubs and restaurants will vary between tiers, but will be tougher overall than under the previous system, addressing a well-identified source of infection but dismaying the hospitality industry. In a bid to “offer communities in tier 3 alert areas a direct route out of the toughest restrictions”, Downing Street announced there would be a significant expansion of the mass testing regime currently being trialled in Liverpool. In a plan endorsed by a cabinet meeting on Sunday afternoon, areas placed into the strictest tier will be offered “extensive community testing”, with assistance from the military. A pilot scheme, in which residents of care homes can have up to two visitors tested twice a week, will also be extended. The bold promises have echoes of earlier plans, which have ended up taking notably longer to fulfil than initially billed. While the Liverpool trial appears to be running well, an initial attempt at mass testing in Salford was halted early amid limited success. In comments released by No 10, Johnson said people’s efforts meant the increase in new cases “is flattening off”. He said: “We are not out of the woods yet. The virus is still present in communities across the country, and remains both far more infectious and far more deadly than seasonal flu. But with expansion in testing and vaccines edging closer to deployment, the regional tiered system will help get the virus back under control and keep it there.” Downing Street was keen to bill the new schemes as purely a way to assist the hardest-hit communities. However, the announcement could also prove potentially significant in swaying dozens of rebel Conservative MPs who are objecting to the return of the regional tiers. In a starkly worded letter to the prime minister, 70 Tory MPs from the newly formed Covid Recovery Group said the government must prove the new restrictions “will save more lives than they cost”. The letter, also signed by 14 Conservative peers, told Johnson that a tiered system “infringes deeply upon people’s lives with huge health and economic costs”. They wrote: “We cannot support this approach further unless the government demonstrates the restrictions proposed for after 2 December will have an impact on slowing the transmission of Covid, and will save more lives than they cost. “To this end, [the] government must publish a full cost-benefit analysis of the proposed restrictions on a regional basis so that MPs can assess responsibly the non-Covid health impact of restrictions, as well as the undoubted impact on livelihoods.” The chancellor, Rishi Sunak, played down the idea of producing such a document. “It’s very hard to be precise in estimating the particular impact of a one-week restriction,” he told Sky’s Sophy Ridge on Sunday. While a failure to win round the discontented MPs could leave Johnson with the uncomfortable prospect of having to rely on Labour when the plan is voted on in the Commons next week, there is increasing scientific pressure for the new tiers to be tougher than those in place before the current four-week England-wide lockdown. A new study led by academics from the University of East Anglia has concluded that the previous tier 1 had “little impact” on the transmission of coronavirus locally. The study, which has not yet undergone peer review, examined infection rates over 14 days in regions placed into the three tiers. It found that the top tier, which barred all household mixing, had the most impact, while the impact in tier 2 was mixed. Prof Paul Hunter, who led the study, said: “Our conclusion is that the problem with the tier system was not actually the tiers, but the inability of the government in England to allocate local authorities to their most appropriate tier quickly enough.” On Sunday, a further 398 people died of coronavirus, according to the government’s daily UK figures, up from 168 the same day the previous week. A total of 18,662 people tested positive for the virus, down from 24,962. Johnson is also due to outline what is expected to be a period of a few days over Christmas in which limited mixing will be allowed between households across the UK. Michael Gove, the Cabinet Office minister, met leaders of the devolved administrations over the weekend, at which, according to his department, they “endorsed a shared objective of facilitating some limited additional household bubbling for a small number of days”. The public will be “advised to remain cautious” and told that “wherever possible people should avoid travelling and minimise social contact” under the plans, which are expected to be finalised this week, the statement said. One element of the previous tiers that is expected to be ditched is the forced 10pm closing time for pubs and restaurants, with people given an extra hour to finish the drinks and food they have already purchased.