Tesco Extra in Abingdon - one of the supermarket giant's biggest stores - remains closed due to flooding.
Staff were alerted during the night on Saturday to the flooded out car park following a flood alert for the River Ock, from Watchfield to Abingdon, and also for Letcombe Brook at Wantage, Grove and East Hanney.
The store off Marcham Road was shut yesterday and remains closed today.
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Tesco has not yet said when it will reopen.
A Tesco spokesperson said: “We are really sorry for any inconvenience caused by the temporary closure of our Abingdon Extra store.
"This is due to the nearby river. The store is currently closed while we work with our maintenance team to ensure the store is safe for colleagues and customers."
The Abingdon Facebook page shared an aerial photo with the Oxford Mail showing the extent of flood waters around the store.
Staff at the site said only about 10 staff had been called in - on a normal day's trading there would be at least 100.
The only access to the store entrance area is via duckboards and click and collect services have also been affected as drivers are unable to get out of the car park.
The Tesco petrol station is also closed.
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A member of staff said earlier: "All the shelves were stacked and ready but we couldn't open - the car park is flooded and the water is coming right up to the cashpoint.
"The water has also come right round the back of the store where the dot com vehicles are parked."
The Tesco store locator website indicates the store is closed and says it will be opening 6am Tuesday.
Some residents on Abingdon Facebook have questioned why the store had been built on a flood plain.
The Environment Agency had issued a flood alert for the area on Friday.
Tesco apologised for the inconvenience and told the BBC it was working with its maintenance team "to ensure the store is safe for colleagues and customers".
Photo: James Davis
A new Premier Inn is currently being built next to the supermarket building.
Flood water has got close to the construction site.
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Building work is still ongoing but the hotel group said last year it was expected to open later this year.
The chain owned by Whitbread already has a hotel a short distance away in Marcham Road but now is building a second one in the town.
The opening of the new four-storey Premier Inn next year will not affect the running of the existing one.
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This story was written by Andy Ffrench. He joined the team more than 20 years ago and now covers community news across Oxfordshire.
Get in touch with him by emailing: Andy.ffrench@newsquest.co.uk
Follow him on Twitter @OxMailAndyF
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