A further 20 million people are under tighter restrictions after the government announced an extension of Tier 4 rules in England in a bid to curb the spread of coronavirus.
On the day the Oxford/AstraZeneca vaccine was approved to tackle COVID-19, Prime Minister Boris Johnson said a new strain of the virus was "surging across the country" and immediate action was needed.
Areas escalated to Tier 4 at 00.01am on Thursday include large parts of the Midlands, North East, parts of the North West and parts of the South West.
The Isles of Scilly is the only area in England still in Tier 1, with the region not reporting any coronavirus cases since September.
Health Secretary Matt Hancock said that although the changes will "place a significant burden on people, and especially on businesses affected", they were "absolutely necessary because of the number of cases that we've seen".
He told MPs: "Sharply rising cases and the hospitalisations that follow demonstrate the need to act where the virus is spreading."
Mr Hancock spoke as concerns grow about a new variant of the virus, which appears to be more transmissible and which he said was "now spreading across most of England".
Referring to new tier allocations announced by Mr Hancock, Mr Johnson told a Downing Street briefing: "At this critical moment, with the prospect of freedom within reach, we've got to redouble our efforts to contain the virus.
"No-one regrets these measures more bitterly than I do, but we must take firm action now."
It comes as the UK recorded 981 deaths within 28 days of a positive COVID-19 test on Wednesday - the highest number since 24 April. The high fatality figure could be partly down to a delay in reporting deaths over Christmas.
The number of new infections reported in the 24 hours to 9am on Wednesday was 50,023 - slightly down on Tuesday's 53,135 which was the most since the pandemic began.
Political leaders in areas placed into the highest COVID-19 restrictions have called on the government to consider a national lockdown.
Six council leaders, two mayors and a police and crime commissioner came together in the North East of England to issue a statement after the whole of the region was plunged into Tier 4 from Thursday.
They said: "Our view is that the government should consider a national lockdown now to ensure the spread of the new variant is slowed and efforts can be focused on the crucial rollout of the vaccine. This is a national problem and a national solution is required now."
Education Secretary Gavin Williamson announced that the return of many schools will be delayed beyond the government's earlier promise.
Exam year students will return on 11 January, with other secondary school students to follow a week later on 18 January, to enable preparations for the testing of pupils and staff to take place.
Tier 4 restrictions include a warning to stay at home, a limit on household mixing to two people outdoors, and the closure of non-essential shops, as well as hairdressers and gyms.
Areas that will be covered by the Tier 4 rules from 00.01am on Thursday are:
Leicestershire - Oadby and Wigston, Harborough, Hinckley and Bosworth, Blaby, Charnwood, North West Leicestershire, Melton
Lincolnshire - City of Lincoln, Boston, South Kesteven, West Lindsey, North Kesteven, South Holland, East Lindsey
Northamptonshire - Corby, Daventry, East Northamptonshire, Kettering, Northampton, South Northamptonshire, Wellingborough
Derby and Derbyshire - Derby, Amber Valley, South Derbyshire, Bolsover, North East Derbyshire, Chesterfield, Erewash, Derbyshire Dales, High Peak
Nottingham and Nottinghamshire - Gedling, Ashfield, Mansfield, Rushcliffe, Bassetlaw, Newark and Sherwood, Nottinghamshire, Broxtowe
Birmingham and Black Country - Dudley, Birmingham, Sandwell, Walsall, Wolverhampton
Warwickshire - Rugby, Nuneaton and Bedworth, Warwick, North Warwickshire, Stratford-upon-Avon
Staffordshire and Stoke-on-Trent - East Staffordshire, Stafford, South Staffordshire, Cannock Chase, Lichfield, Staffordshire Moorlands, Newcastle under Lyme, Tamworth, Stoke-on-Trent
Lancashire - Burnley, Pendle, Blackburn with Darwen, Ribble Valley, Blackpool, Preston, Hyndburn, Chorley, Fylde, Lancaster, Rossendale, South Ribble, West Lancashire, Wyre
Cheshire and Warrington - Cheshire East, Cheshire West and Chester, Warrington
Cumbria - Eden, Carlisle, South Lakeland, Barrow-in-Furness, Copeland, Allerdale
Greater Manchester - Bolton, Bury, Manchester, Oldham, Rochdale, Salford, Stockport, Tameside, Trafford, Wigan
Tees Valley - Darlington, Hartlepool, Middlesbrough, Redcar and Cleveland, Stockton-on-Tees
North East - County Durham, Gateshead, Newcastle-upon-Tyne, North Tyneside, Northumberland, South Tyneside, Sunderland
Gloucestershire - Gloucester, Forest of Dean, Cotswolds, Tewkesbury, Stroud, Cheltenham
Somerset council - Mendip, Sedgemoor, Somerset West and Taunton, South Somerset
Bournemouth, Christchurch and Poole
Isle of Wight