The latest tier review in England has been announced by Health Secretary Matt Hancock.
Mr Hancock told MPs that Tier 3 restrictions will be extended across a wide area of East and South East England.
Bedfordshire, Buckinghamshire, Berkshire, Peterborough, the whole of Hertfordshire, Surrey with the exception of Waverley, Hastings and Rother, Portsmouth, Gosport and Havant will move into Tier 3 restrictions.
However, only a few areas will be moved down a tier. The Health Secretary announced that Bristol and North Somerset will move down a tier, from Tier 3 to Tier 2, with Herefordshire moving down a tier, from Tier 2 to Tier 1.
These changes will come into effect at 12.01am on Saturday (19 Dec).
Large parts of the Midlands, Yorkshire, the North East and the North West will remain under Tier 3 restrictions, despite leaders in numerous areas of northern England saying they have met the criteria to be able to move down to Tier 2.
Greater Manchester mayor, Andy Burnham, previously said that although "the evidence would support" parts of the region being moved down to Tier 2 from Tier 3, he felt "less and less hopeful" about this being the case.
London and parts of Essex and Hertfordshire moved to Tier 3 on Wednesday (16 Dec), after a rise in coronavirus infection rates.
Mr Hancock told the Commons that everyone has a "personal responsibility to play their part in keeping this pandemic under control.”
“It’s so vital that everyone sticks at it and does the right thing, especially over this Christmas period," added the Health Secretary.
“It’s important to remember that this can be a silent disease. One in three people who have the disease has no symptoms but can still pass it on.
Debate over Christmas break
The tier changes announced today will come into place on Saturday and remain in place until 23 December, when there will then be a five day long Christmas break in restrictions. This will end on 27 December.
This temporary break in restrictions has recently sparked debate between scientists and government officials, with differing advice on the best course of action to take over the Christmas period.
In a joint editorial from the British Medical Journal and Health Service Journal, the two medical journals said that the government could no longer claim to be protecting the NHS if it went ahead with its plans to allow up to three households to mix indoors over the Christmas period.
The leading journals said, “We believe the government is about to blunder into another major error that will cost many lives.”
However, after a discussion between the four devolved administrations, Boris Johnson announced on Wednesday that Christmas plans could still go ahead, but that celebrations should be kept both "short" and "small" in order to reduce the risk of spreading Covid.
In Wales, a new law change will mean that only two households will be able to meet over the five day period, and people in Scotland have been asked to meet on only one of the five days.