it to be effective against covid, and scientists believe it may be effective against new variants such as the omicron variant. 3 december the number of confirmed cases of omicron in the uk exceeds 100. the health security agency publishes a risk assessment of the new variant. a uk study trialling different covid vaccines suggests the pfizer and moderna vaccines provide the best overall immunity response when used as booster doses. conservative party chairman oliver dowden says he has no plans to cancel conservative party christmas parties after labour said its parliamentary christmas party would not be going ahead. dowden says he would "urge people to keep calm and carry on with their plans". the first case of omicron variant covid is identified in wales. 4 december health secretary sajid javid confirms that travellers to the uk will need to take a pre-departure covid test from 4:00am on 7 december. gp surgeries in england will be allowed to defer non-urgent health checks for over-75s in order to focus on providing the booster vaccine. the move is welcomed by doctors' leaders. following calls from two labour mps for a police investigation into the christmas party held in downing street on 18 december 2020, the metropolitan police says it does not routinely probe "retrospective breaches" of covid laws, but will do so on this occasion. 5 december a further 86 omicron cases are found in the uk, bringing the total to 246. sage member professor mark woolhouse describes the new travel regulations as "a case of shutting the stable door after the horse has bolted". 6 december health secretary sajid javid confirms there is community transmission of omicron variant covid in several communities within england, with a total of 336 uk cases confirmed so far. a trade body describes the uk government's website for finding covid tests as "not serving its purpose" amid warnings about misleading prices. 7 december new travel rules requiring people to take a pre-departure covid test before travelling into the uk come into force. the official spokesman for prime minister boris johnson says early evidence suggests the omicron variant of covid is more transmissible than the delta variant, but that any impact caused by it will determine on whether it causes severe illness; currently there are 437 cases of the new variant in the uk. a video obtained by itv news shows senior downing street staff joking about a party days after one was held while the uk was under covid restrictions in december 2020, and as the government continues to claim no party occurred. keir starmer says "they knew there was a party, they knew it was against the rules, they knew they couldn't admit it, and they thought it was funny". starmer maintains the government have lost the moral authority to lead. scottish first minister nicola sturgeon announces plans to review covid rules on a daily basis amid concerns about the rise in numbers of cases of the omicron variant; a total of 99 have now been identified in scotland. the first case of the omicron variant is identified in northern ireland, and is believed to be linked to travel from the uk mainland. 8 december the booster jab program opens to over-40s, meaning an extra seven million people can get a third vaccine dose. a leaked copy of the minutes of a sage meeting contains speculation that the omicron variant could lead to 1,000 hospitalisations per day by the end of the month. allegra stratton resigns as the downing street press secretary after video footage of staff joking about a christmas party emerged. the metropolitan police confirms it will not investigate the downing street christmas party. at a downing street press conference, prime minister boris johnson announces new plan b rules for england that will see masks become compulsory in all indoor public places from friday 10 december, and a requirement for covid passports in order to enter nightclubs and other large venues from wednesday 15 december. people will also be advised to work from home if they can from monday 13 december. at the same press conference johnson says that although there are no plans for mandatory vaccinations in the uk, there needs to be a "national conversation" about protecting the public. the nhs covid pass crashes within hours of the above announcement. 9 december the conservative party confirms that a party, separate to the one at downing street, was held at its headquarters by shaun bailey's mayoral campaign in december 2020. the telegraph reports the party "featured dancing and wine-drinking into the early hours despite indoor social mixing being banned at the time". paymaster general michael ellis confirms a cabinet office investigation into the downing street party held on 18 december 2020 will look at two other events held while england was under covid restrictions; a leaving party for a downing street employee on 27 november 2020, which was allegedly attended by the prime minister, and a christmas party at the department for education on 10 december. fresh developments emerge over the downing street christmas party controversy, with allegations jack doyle, who at the time was deputy director of communications, gave a speech and handed out awards to 50 attendees. the uk health security agency says that omicron cases are doubling every 2.5 to 3 days, and predicts that recorded cases are underestimated. the agency forecasts there could be over a million cases by the end of december 2021. 10 december the uk records 58,194 daily covid cases, its highest number since january 2021. the uk health security agency forecasts that the omicron variant could be the dominant strain of covid by the end of december, with a million cases; 581 have been confirmed to date. early analysis also suggests two vaccines are less effective against the omicron variant than the delta variant, but that a third vaccine provides 70–75% protection against developing covid symptoms. new guidelines for care homes in england restrict residents to three visitors and one essential care provider. former downing street chief adviser dominic cummings tells sky news there are pictures of the 2020 downing street christmas party that will "inevitably get out", and that there were "invites sent across whitehall". bbc news reports that downing street denies claims that jack doyle offered his resignation as downing street director of communications in the wake of revelations he gave a speech at the 18 december gathering and that it was rejected. uk residents who received their vaccine overseas or in northern ireland are now eligible to use england's nhs covid pass. 11 december a study published by the london school of hygiene and tropical medicine suggests a substantial increase in the number of omicron variant cases in january 2022 without further restrictions, with a prediction of double the number of hospitalisations compared to winter 2020–21 and anything from 25,000 to 75,000 deaths by april 2022. but the scientists behind the study say its modelling is uncertain, while its worst case scenario is dismissed by infectious diseases expert professor paul hunter as unlikely. a further 633 omicron cases are identified in the uk in the largest daily increase so far. fresh allegations emerge of another civil service gathering while england was in lockdown in late 2020, with reports that two dozen hm treasury staff gathered for drinks on 25 november to celebrate chancellor rishi sunak's autumn spending review. 12 december downing street confirms that prime minister boris johnson took part in an online virtual christmas quiz on 15 december 2020 after the sunday mirror publishes a picture of him on a screen during the event. the independent reports that senior police officers fear people will be less likely to comply with any new covid restrictions because of the scandal surrounding parties held by downing street and uk government departments. the newspaper says they have gathered anecdotal evidence of terse exchanges between police officers and members of the public in the days following the onset of the scandal. the uk covid alert level is raised from three to four by the four chief medical officers due to the spread of the omicron variant. johnson brings forward the booster programme for all eligible people from the end of january to the end of december, declaring "there is a tidal wave of omicron coming"; the booster programme will be extended to all over 18s from the following day. people in england who have received both vaccines will be told to take daily lateral flow tests if they have been in close contact with someone who tested positive for covid from tuesday 14 december. 13 december the first uk death linked to the omicron variant is reported. health secretary sajid javid says the omicron variant now makes up 20% of the new covid cases in england, and is expected to become the dominant variant in london in 48 hours. the uk government announces that members of the armed forces will be drafted in to help with the booster programme. the nhs website crashes as thousands of people in england attempt to book their booster vaccines. bbc news reports that around 70 conservative mps are expected to vote against tighter covid restrictions when they are brought before parliament later in the week. speaking about the westminster christmas parties controversy, prime minister boris johnson says he "certainly broke no rules". covid passes become enforceable for hospitality businesses in northern ireland, with a £10,000 fine for any venue that does not comply. 14 december mps vote 369–126 in favour of introducing covid passes for nightclubs and large venues in england, with 100 conservative mps voting against the measure, the largest conservative rebellion since boris johnson became prime minister. mps also vote in favour of the use of compulsory face masks in most indoor settings, replacing mandatory self-isolation with daily lateral flow tests for any fully-vaccinated people who come into contact with someone testing positive for covid, and compulsory vaccines for nhs and other healthcare workers from april 2022. the measures become law from the following day. the uk removes all 11 african countries from the travel red list, allowing easier travel between them and england. anyone quarantining in a hotel will also be allowed to leave early. the uk records 59,610 new covid cases, the largest number since january, and there is a warning from professor chris whitty, england's chief medical officer, that hospitalisations will face a significant increase in the number of admissions. scotland's first minister, nicola sturgeon, urges people to limit their gatherings to three households in the run up to christmas. dr angelique coetzee, the south african physician who first raised the alarm about the omicron variant, and who has been asked to look at the uk government's response to it by the house of commons science and technology select committee, suggests prime minister johnson has over reacted to the situation and is creating "hysteria". coetzee tells sky news there is a "huge gap" between "the science and what is actually happening". 15 december the uk records its highest number of daily cases since the pandemic began, at 78,610. england's chief medical officer, professor chris whitty warns that covid records "will be broken a lot" in the coming weeks as cases increase. a leaked photo emerges of former london mayoral candidate shaun bailey and 23 colleagues holding a christmas party at the conservative headquarters in london, during the covid-19 restrictions of december 2020. business groups have urged the government to provide assistance to companies impacted by a rise in covid cases. hotel quarantine guests in england are told they can leave as long as they have a negative covid test, and they will be refunded. more than 30 local authorities have told the bbc their schools are prepared to switch to online learning again after christmas should that be required, with children being given laptops to take home over the holidays. the scottish hospitality sector estimates it has taken a "£1bn hit" because of cancelled events in the run up to christmas. 16 december a further 88,376 new covid cases are reported, while 745,183 booster vaccines are given. first minister of wales mark drakeford announces the closure of nightclubs in wales from 27 december as a result of the spread of the omicron variant. the daily mirror reports another westminster staff christmas party