Tesco's store in Luton's The Mall is expected to remain closed until mid-November at the earliest, the company has stated.
The store was initially due to close for refurbishment on April 26, however the closure was deferred by the company until June 16.
The Luton News understand that the store had not been refitted in decades and was in substantial need of renovation work.
A Tesco spokesman said: "We’re pleased to announce that we’re refreshing our Luton Metro store, bringing a new look and feel to the shop for our customers.
"The store temporarily closed on 16th June and we expect the work to take between five and six months to complete.
"We apologise for any inconvenience caused to our customers during the closure and we hope customers enjoy the refreshed store once we reopen in later this year."