With millions of people in the UK facing the possibility of working from home or self-isolating, there has been enormous pressure on supermarket stocks.

Britain's leading supermarkets placed a full-page advert in newspapers this week pleading with customers to stop panic buying to avoid others going without. The industry says it is working night and day to feed the nation and is looking for ways to improve and protect the supply chain.

"Supermarket supply chains are extremely robust. The real challenge for them at the moment is that consumers are stripping stuff off the shelves at an unprecedented rate," said Janet Godsell, professor of operations and supply chain management at Warwick University.

Some stores have started rationing items. Aldi is limiting customers to just four of any item, while others are limiting specific goods such as toilet paper, pasta and wet wipes. If stockpiling continues, the government may be forced to step in to ensure essential goods are available to the most vulnerable.

Meanwhile, supermarkets are trying to build up extra stock at their warehouses. The government has already eased restrictions on night time deliveries to supermarkets and is considering allowing drivers to work longer hours. 

Many companies are also actively trying to recruit more drivers but may face greater difficulties finding additional suitable vehicles as many food delivery lorries need to be temperature controlled.

Imports

Border closures across Europe and flight restrictions are posing additional challenges. Although deliveries should be able to get through, some foodstuffs may become more difficult to source – with the UK relying on imports for more than half of its food. 

While Britain may be behind the curve of other European countries in the number of cases of Covid-19, that has only given more time for people to plan to be stuck at home and stock up on essential items, if they can find them.

Godsell is confident that the stores won't run out of food and other items but shoppers may find a more limited choice of goods: "Rest assured the majority of the items, the stuff will be out there in the supply chain. There is plenty of pasta, but you may find you can't get the fancy brand of Italian pasta you like."

Panic buying has also hit online grocery shopping, with vulnerable groups such as the elderly and those with other health problems relying on deliveries after being told not to leave their homes. 

Two supermarket websites crashed this week and one company has stopped accepting new customers, while others face week-long delays.