The bulk of lockdown measures may be in place in England until March, a Government minister has warned.
Cabinet Office minister Michael Gove said the country was in for a "very difficult" few weeks and could give no firm date for lifting the restrictions.
People cannot leave their homes except for essential reasons, and schools and colleges will close from today.
Gove told Sky News this morning: "The Government is doing everything it can in order to ensure that we can roll out the vaccine more rapidly, help the vulnerable by getting the inoculations they need and make sure that at the end of what will inevitably be very, very difficult weeks, that life can eventually return to normal."
Pressed on whether the lockdown was likely to last until March, Gove added: "We will be able to review the progress that we've made on February 15, just before the traditional school half-term, and we hope that we will be able to progressively lift restrictions after that but what I can't do is predict – nobody can predict – with accuracy exactly what we will be able to relax and when.
"What we do know is that the more effective our vaccination programme, the more people who are protected in that way, the easier it will be to lift these restrictions."
However, he believes March should mark the point at which restrictions will start to be lifted.
Gove continued: "We will keep these constantly under review but you are absolutely right, we can't predict with certainty that we will be able to lift restrictions in the week commencing February 15-22.
"What we will be doing is everything that we can to make sure that as many people as possible are vaccinated, so that we can begin to progressively lift restrictions.
"I think it is right to say that as we enter March we should be able to lift some of these restrictions but not necessarily all."
On Monday, January 4, the UK recorded more than 50,000 new coronavirus cases for the seventh day in a row, along with 407 deaths.
A police federation leader warned that enforcing the new lockdown in England will put "a lot of pressure" on officers whose numbers are already reduced by the pandemic.
Ken Marsh, chairman of the Metropolitan Police Federation – which represents front line officers in London – said some 1,300 were off sick or self-isolating in the capital.
His counterpart nationally, John Apter, wrote in the Daily Telegraph some forces were reporting 15% of their staff off sick or self-isolating.
Mr Marsh urged the Government to place police officers on a priority list to receive coronavirus vaccines, saying requests so far were "falling on deaf ears".
Anyone violating the new rules faces a fixed penalty notice of £200 for a first offence, with this doubling for further offences up to a maximum of £6,400.
Those holding, or involved in holding, an illegal gathering of more than 30 people risk a police-issued fine of £10,000.