To help ensure customers wear the face coverings, marshals will be positioned at the entrances of all supermarkets and will have disposable masks available for customers who do not have their own and will refuse entry to anyone who fails to comply with the new rules.
The marshals will also be wary that, wherever possible, only one member of each household is permitted to shop.
Employees at Waitrose will now be required to wear face coverings when behind protective perspex screens and in back of house areas, in addition to the other areas where this rule already applies.
The group said its Click and Collect services will be switched off to new orders at the close of business.
Andrew Murphy, executive director of operations at John Lewis Partnership, said: “We are acutely aware that the country is at a critical point in the pandemic and are constantly thinking about how best the Partnership and our Partners can play our part in limiting the spread and impact of the virus.
“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. While we recognise that the detail of formal guidance has not changed, we feel it is right for us – and in the best interests of our Partners and customers – to take proactive steps to further enhance our covid-security and related operational policies.”
He added: “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.
“Meanwhile, we will reduce the range of services we are offering to carry out in customers’ homes, focusing only on those which are essential in order for customers to maintain their health and wellbeing and that of their families.”