Two supermarket chains has said they will be enforcing mask wearing in store.

Sainsbury's will enforce mask wearing and shopping alone in its stores, the company has said.

The superstore has written to customers to ask them to play their part in keeping everyone safe, and said it has "significantly reduced" the number of customers allowed into stores at any one time.

Simon Roberts, chief executive of Sainsbury's, said: "I have spent a lot of time in our stores over the past few days and I need to ask for your help with two key issues to keep you and all my colleagues safe.

"When shopping in our stores, you must wear a mask or visor unless you have a medical exemption. And you should also shop on your own. Thank you for your support.

"Security guards will support our colleagues at the front of store and will challenge customers who are not wearing masks or who are shopping in groups. I know you’ll understand and support what we are trying to do.

"We have also significantly reduced the number of customers allowed in our stores at any one time to ensure social distancing is maintained at all times.

"Together, these steps will go a long way to keep everyone safe, whether you are shopping or working with us.

"Please wear a mask or visor and please shop alone in our stores. Thank you for helping us to keep everyone safe."

Since the start of the pandemic Morrisons have introduced and consistently maintained thorough and robust safety measures in all stores. These include managed store entrances, plastic screens, free face coverings, managed checkout queues, rigorous and regular cleaning and clear signage and instructions for customers. From today Morrisons are further strengthening our policy on masks.

Morrisons 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.”