Lockdown restrictions have been tightened across the UK in an effort to curb the spread of Covid-19, with England entering its third national lockdown by law on 6 January 2021.
The tough new restrictions are expected to remain in place until at least mid-February, and all non-essential retailers have closed their doors once again.
Similarly in Scotland, a legally-enforceable stay at home order now applies to areas currently under Level 4 - mainland Scotland and Skye - with residents only permitted to leave home for limited exemptions.
While supermarkets remain open across the UK, many major stores have increased some safety precautions in an effort to control queues and ease the flow of shoppers during busy periods.
Some shops are now encouraging shoppers to visit alone to help minimise the number of people inside, while others have put additional store marshalls in place.
Here are all the rules and services you need to know about at some of the UK’s major supermarkets.
Asda will deny entry into its stores if shoppers are not wearing a face mask, unless they are medically exempt. If customers forget their face coverings, the supermarket will offer them one free of charge.
Extra security staff and safety marshals will be on duty at the entrance of each store and a traffic light system will be used to ensure a safe number of people can shop at any one time, while maintaining social distancing.
Protective screens are in place at all checkouts and sanitisation stations will be located in stores, along with social distancing markers.
Contactless payments are encouraged, with a limit of £45, and NHS, Blue Light and vulnerable customers will have priority access at specific times.
Sainsbury’s will now enforce the wearing of masks in all of its stores, as well as shopping alone rather than in groups.
The supermarket has said it has “significantly reduced” the number of customers permitted into its stores at any one time, and trained security guards will now be in place at store entrances to ensure rules are enforced.
Perspex safety screens are already in place between checkouts, along with hand sanitiser stations, signs for social distancing, additional cleaning in stores and queuing systems outside of stores will be implemented during busy periods.
Elderly and vulnerable customers will have priority for online delivery slots, as well as entry to stores from 8am to 9am on Monday, Wednesday and Friday. NHS staff and care workers still have priority entry from 7.30am to 8am between Monday and Saturday.
Aldi is encouraging shoppers to pick quieter times to do their shopping, typically between 7pm and 10pm, and asks that people 'come alone if possible', with customer numbers dramatically reduced across its stores.
NHS and emergency service staff will be given priority access to the store and Aldi is advising people to make use of its new click and collect service, which is available in more than 200 stores.
Tesco will no longer permit entry to shoppers who do not wear a face mask, unless they are medically exempt.
A spokeswoman said: "To protect our customers and colleagues, we won't let anyone into our stores who is not wearing a face covering, unless they are exempt in line with government guidance.
"We are also asking our customers to shop alone, unless they're a carer or with children. To support our colleagues, we will have additional security in stores to help manage this."
The supermarket is also continuing to limit the number of customers allowed in stores at once and has introduced a 'one-in, one-out' system.
Customers should now only enter stores alone, but those with a carer or children are permitted to shop together.
Hand sanitiser and cleaning stations are in place around stores, and packs of face masks will be available to buy at some entrances which can be opened immediately and paid for with shopping later.
Tesco is continuing its dedicated hours for vulnerable customers, as well as NHS, emergency service and care workers.
Morrisons has also strengthened its mask policy and has confirmed that customers who refuse to wear a mask, without a medical exemption, will now be told to leave stores.
Chief executive David Potts said: “Those who are offered a face covering and decline to wear one won’t be allowed to shop at Morrisons unless they are medically exempt. Our store colleagues are working hard to feed you and your family, please be kind.”
NHS workers still have priority access to stores from 6am to 7am from Monday to Saturday, and 9.30am on Sunday.
Customers are being encouraged to book their food shop delivery well in advance due to high demand, with next day delivery offered to those who are self-isolating or unable to get to a store by calling 0345 611 6111 and selecting option five.
Queues will be managed outside by allowing customers doing a smaller shop to enter first, with three basket shoppers allowed in for every one shopper with a trolley.
Marks & Spencer
Marks & Spencer has introduced a new Sparks Book & Shop service to allow shoppers to skip the queues and reserve a slot that suits them.
The service means you can queue virtually and arrive for a pre-booked 30 minute shopping slot without having to wait.
Customers can also use the M&S app and select contactless delivery to their door, or use the free click and collect service at more than 600 stores.
Similar to several other supermarkets, Waitrose will also not allow entry to customers who are not wearing a face mask, unless they are medically exempt.
Andrew Murphy, executive director of operations at Waitrose, said: "We've listened carefully to the clear change in tone and emphasis of the views and information shared by the UK's governments in recent days.
"By insisting on the wearing of face coverings, over and above the social distancing measures we already have in place, we aim to make our shops even safer for customers."