Shoppers warned that they will have to wear a mask when they go into Hemel Hempstead supermarkets

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 January 6.

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.

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 marshals in place.

The move comes as Prime Minister Boris Johnson urged the public to respect Covid-19 regulations while grocery shopping.

He warned the public against “false complacency” and that “in supermarkets, people need to be keeping their distance, making sure that they’re wearing masks, doing the right thing”.

Here are all the rules and services you need to know about at some of the UK’s major supermarkets.

Asda

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

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 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

Aldi has put a traffic light system in place and is encouraging shoppers to pick quieter times to do their shopping, typically between 7pm and 10pm.

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

Tesco has introduced a traffic light system to help limit the number of people in some stores during busy periods, and will operate a ‘one in, one out’ rule to maintain social distancing.

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.

The supermarket is also continuing its dedicated hours for vulnerable customers, as well as NHS, emergency service and care workers.

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.

Health Secretary Matt Hancock praised the actions taken by Sainsbury's and Morrisons - who are also enforcing the wearing of face masks in store - stating that the stronger enforcement of Covid-19 regulations is “necessary”.

He said: “It isn’t just about the Government and the rules we set, or the police and the work that they do - it’s about how everybody behaves.

“I applaud the action Morrisons has taken today, the supermarket, they have said that they will not let people in without a mask unless they clearly have a medical reason.

“That’s the right approach and I want to see all parts of society playing their part in this.”