Thousands of Tesco customers have had their grocery deliveries cancelled or postponed following a computer glitch.

The supermarket giant said it is "working hard" to fix the problem, which began on Tuesday morning and is centred on customer orders and fulfilment from some stores.

A spokesman said less than 10 per cent of customers are affected, and he apologised for "any inconvenience".

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Some affected customers took to social media, with one writing: "What do we do about no grocery deliveries today? How do we get a reschedule? My numbers not on system and had no email #nofoodforus."

Another said: "Just had a call to say all Tesco home deliveries have been cancelled today because of a national system failure."

The Tesco spokesman said: "We're currently experiencing an IT issue which is affecting some grocery home shopping orders.

"We're working hard to fix this problem and apologise to customers for any inconvenience this may cause."