Online shopping delivery service Ocado has suspended its online food delivery service, blaming higher demand than it can meet.
Ocado said existing customers with orders would still receive them.
Meanwhile, supermarkets have introduced strict limits on how many goods people can buy to try to curb stockpiling as the coronavirus pandemic escalates.
Tesco, Sainsbury's and Asda will now stop shoppers buying more than three of any particular food item.
Sainsbury's has also said it will prioritise vulnerable and elderly people for online deliveries.
Ocado said it was experiencing "a simply staggering amount of traffic" to its website and more demand for products and deliveries than it could meet.
"This temporary closure will allow us to complete essential work that will help to make sure distribution of products and delivery slots is as fair and accessible as possible for all our loyal customers," it added.
Asda and Sainsbury's buying restrictions will also apply to cleaning and toiletry products, while Tesco's limits will apply to all products.
"If you could help us by limiting demand of essential items and allowing us to focus on the core needs of our customers - we are confident that we can continue to feed the nation," said Tesco.
Asda said it had seen "a heightened demand" for products both in stores and online.
"We have plenty of products to go around, but we have a responsibility to do the right thing for our communities to help our customers look after their loved ones in a time of need," it added.
Asda told the BBC that cashiers and customers using self-checkout would not be able to scan more than three of the same restricted items. Sainsbury's said it was updating its tills to reflect the limits.
Aldi has already introduced limits of four items per shopper on all products, while Morrisons has said it will expand its online delivery service.
Other retailers including Tesco and Boots have set limits on particularly popular products such as pasta, tissues and hand sanitiser.
Boots chief executive Sebastian James said the issue was not supply, but demand.
"No supply chain can survive a sudden, unexpected global ten-fold increase in demand. And what we thought was incredibly important was that as many people as possible could get what they actually needed," he told the BBC's Today programme.
Supermarkets' online delivery services have also been overwhelmed by the surge in demand. Before Ocado suspended its whole service it had taken down its app due to the spike in orders.
Others meanwhile vented their frustration on Twitter at being one of thousands in a virtual queue to place a food order.
Really @Ocado ?? I just want to amend my delivery that is scheduled for Thursday morning but the app isn't working and this is what is happening with the website. Appreciate that things are a bit crazy right now, but I dont want to order things I dont need 😔 pic.twitter.com/ZK5sy08jUz— Gemma Brown MCMI MCIM (@G_LBrown) March 17, 2020
Other businesses have also announced new measures to combat the coronavirus pandemic, including:
- Amazon: The online retailer is stopping sellers from sending "non-essentials" to its US and UK warehouses to make space for sought-after baby products and groceries.
- Pret: From Thursday the chain will no longer allow customers to sit in-store, "to reduce points of contact" in shops.
- Selfridges: The luxury department store chain will temporarily close its four shops from 19:00 on Wednesday, but will continue trading online.
Supermarket chain Sainsbury's already had a two-item limit on its most popular goods, including toilet paper, soap and long-life milk. From 23 March, it said disabled customers and those over 70 will be given priority for online delivery slots.
And on 19 March the first hour of shopping will be dedicated to older and vulnerable people in its 600 UK stores.
The chain follows other supermarkets in introducing reserved time slots for the elderly. They include Iceland outlets across the country and all 39 Lidl stores in Northern Ireland.
Sainsbury's told the BBC that it would consider future dedicated shopping hours "in line with government guidance", after the one-off on Thursday.
Getting food onto shelves
Sainsbury's chief executive Mike Coupe added it was "focusing all of our efforts on getting as much food and other essential items from our suppliers, into our warehouses and onto shelves as we possibly can.
"We still have enough food for everyone - if we all just buy what we need for us and our families."
Mr Coupe confirmed that it was closing its cafes as well as its fish, pizza and meat counters to free up more staff to work on "keeping the shelves as well stocked as possible."
Asda will also temporarily shut down its "non-essential" services including its rotisserie and pizza counters to free up its workers and space in its warehouses.
The announcements came as Transport Secretary Grant Shapps signed off a temporary relaxation of drivers' hours rules to deliver goods to stores around the UK.
We’re helping supermarkets respond to #COVID-19. I’ve authorised a temporary relaxation of the drivers’ hours rules to help deliver vital goods to stores across the UK; with the understanding that driver welfare must not be compromised.— Rt Hon Grant Shapps MP (@grantshapps) March 17, 2020
A Department for Transport statement said the rule change applies only to drivers supplying food and "essential products to supermarkets".
Sainsbury's competitor Morrisons said on Tuesday it is creating 3,500 jobs to meet surging demand for its home delivery service caused by the pandemic.
The chain said it would be recruiting 2,500 pickers and drivers and hiring about 1,000 people to work in distribution centres.
In its preliminary results for the week ending 2 February, its chief executive David Potts said retailers were "facing unprecedented challenges" when dealing with Covid-19.
Despite the increased uncertainty, it said it had seen sales increase in recent weeks due to customers stockpiling.