In the run-up to a holiday season that the British government promised would return to normality after last year’s heavily restricted affair, a weary nation is instead being wracked by a new crisis: Omicron.

Britain’s beleaguered leader faces a major test of his authority on Tuesday, with members of his own Conservative party preparing to rebel against measures on working from home, Covid passports and mask-wearing in a vote in Parliament. He will be forced to rely on support from the opposition Labour Party to pass the new restrictions, which are a significant departure from the government’s pandemic response in recent months. Johnson lifted all Covid-19 rules on “freedom day” in July and has until now resisted the more robust mitigation measures imposed in parts of Europe, like vaccine passports and mask mandates.

The Prime Minister is also embroiled in a scandal over reports that Downing Street held a number of staff holiday parties last winter, when the rest of the UK was living under strict rules banning social mixing. He has been forced to deny that he fast-tracked “Plan B” Covid rules in order to distract from his political woes.

Opening the debate in Parliament on the new Covid regulations Tuesday, UK Health Secretary Sajid Javid said that though the measures were not ones he would like to put in place, the situation demanded them. “As we look ahead to a winter with Omicron in the midst, the measures before the House [of Commons] today will fortify our natural defenses and guard the gains that we’ve all made against this deadly virus,” Javid said.

Scientists have never seen a variant that can spread so quickly and the growth in cases of Omicron in the UK is now mirroring the rapid increase in South Africa, Javid said, warning that the observed doubling time was two days. Until recently, ministers had said that cases were doubling every two to three days.

So far, 10 people in England have been hospitalized with the variant, the health secretary said, warning that even if Omicron turned out to be less severe overall than the Delta variant, its greater transmissibility risks overwhelming the health service, which is already stretched to its limits.

The health secretary added that there may now be as many as 200,000 Omicron infections a day — a figure that the UK Health Security Agency (UKHSA) said was based on modeling — with the strain accounting for 20% of cases in England.

Javid described the “national mission” to get as many people vaccinated as quickly as possible, calling it “a race between the virus and the vaccine.”

The British government has insisted that its new booster drive, which aims to deliver third doses to every adult by the end of December — a month earlier than planned — is the best way to stop the spread of cases and avoid imposing further restrictions.

NHS staff are being redeployed to accelerate the booster vaccination effort, postponing some urgent appointments and elective surgeries until the new year to prioritize third shots.

More than 500,000 booster and third doses were deployed on Monday, according to government data. Around 45% of people aged 18 and over are now estimated to have received a third dose, according to analysis by the PA Media news agency.

But on the same day, the NHS booking system did not appear to be coping with the huge surge in demand for appointments. More than 100,000 people in England booked booster doses overnight, chief executive of NHS England Amanda Pritchard said on Monday. Responding to reports of the website crashing Monday morning, Pritchard acknowledged there had been “some glitches on the system.”

But Pritchard asked members of the public to keep trying, stressing that “more slots are going on all the time.” She also asked those living close to walk-in clinics to make use of this facility if possible, despite people reporting having to queue up in the street for up to five hours.

“Despite describing the current situation as an ’emergency’ with a ‘tidal wave’ of infections on the horizon, the Government’s response relying entirely on the vaccine booster programme is missing the wider measures required to control the spread of Omicron,” Dr Chaand Nagpaul, BMA council chair, said in a statement on Monday.

Other measures debated Tuesday included government plans to introduce Covid passes to enter large venues such as nightclubs. The government has shifted the proposal to allow for the inclusion of a negative lateral flow test, in an attempt to assuage potential rebels.

Javid said that there would always be an option for lateral flow tests, and he would not support a vaccine-only Covid pass system.

The government has also advised fully vaccinated contacts of a Covid-19 case to take daily lateral flow tests for seven days to slow the spread of the virus.

But the UK’s supply of home testing kits — usually available to be ordered from the government’s website — also appeared to run dry on Monday. Users in England logging on on Monday received a message saying “sorry there are no more tests available,” asking them to “try again later.”