Changes to England’s tier system will come into force on Boxing Day, when millions of people will face harsher coronavirus restrictions.

Sussex, Oxfordshire, Suffolk, Norfolk and Cambridgeshire will move into Tier 4, created in response to a variant of Covid-19 discovered in the UK, from Saturday.

The parts of Essex still in Tier 2, Waverley in Surrey and Hampshire including Portsmouth and Southampton, but with the exception of the New Forest, will also move into the toughest tier.

In Tier 4, no household mixing is allowed, though one person can meet one other person outside in a public space, while all non-essential shops and businesses must close, including personal care and indoor entertainment.

Nobody can enter or leave Tier 4 areas and residents must not stay overnight away from home.

Meanwhile, Bristol, Gloucestershire, Somerset including the North Somerset council area, Swindon, the Isle of Wight, the New Forest and Northamptonshire plus Cheshire and Warrington are moving up to Tier 3.

In the “very high” alert level, no household mixing is allowed indoors or outdoors, except in parks and public gardens.

All hospitality is closed, except for takeaways and deliveries, and accommodation and entertainment venues must shut.

Cornwall and Herefordshire are moving up to Tier 2 from December 26, where the main restrictions are no household mixing allowed indoors, but the “rule of six” applies outdoors.

Hospitality venues must close unless serving substantial meals with drinks, while large sport and entertainment events are allowed but with a very limited audience.

The Isles of Scilly, which has a population of just 2,000 people, will be the only area of England remaining in Tier 1.

In the lowest alert level, the “rule of six” must apply indoors and outdoors, while there must be table service in hospitality venues, with last orders at 10pm and closing time at 11pm.