Sainsbury's has been forced to suspend its online shopping service due to technical problems.
Around 10,000 customers are thought to be affected by the outage, which the company is blaming on computer problems affecting its processing system.
The retailer has not given any indication of when the system is likely to be back up and running, though it was keen to stress that no customer details had been put at the risk.
Sainsbury's says it is contacting customers affected by the problems and offering them a 10 e-voucher to spend online to apologise for the inconvenience.
In a statement, Sainsbury's said: "We suspended our online home delivery website late yesterday afternoon when we identified a technical issue. By mid-morning we had already contacted the overall majority of customers who have been impacted to advise them to place their order again once we have resolved the problem.
"We are now starting to call customers who had placed orders for tomorrow as we are now unable to fulfil them and we are working hard to resume normal service as soon as possible and will communicate with customers as soon as this happens.
"Like many online retailers, from time to time we do have technical glitches and only want our customers to have access to a site that we are 100 per cent happy with."
