Tesco is to call time on 24-hour opening at large stores where sales figures no longer justify the operational costs.

In the latest move by CEO Dave Lewis to shore up the supermarket giant’s finances, the Tesco boss has told management that stores will open at 6am and close at midnight in areas with some of the lowest footfalls.

Tesco has already made the decision to shut two of its Extra stores at night, although it is not revealing their location while staff are consulted about the changes, and it is understood other stores will follow suit. Tesco stressed there would be a “limited” impact on jobs, with night operations such as preparation for online deliveries and in-store availability continuing as usual after the doors shut to customers.

Tesco began 24-hour trading in 1996, saying it wanted to help customers shop whenever they wanted to. There are currently 400 Extras and superstores offering the service, and Tesco sources stressed it was not considering ending all 24-hour opening.

However, the costs of the biggest stores have been a key issue for Lewis since he started last year. Lewis inherited what some regard as an albatross around his neck with Tesco’s huge out-of-town stores, which have been hit by the shift to online and the rise of the discounters. He called a halt to 49 future store openings, most of them large stores.

Tesco is part way through its Project Reset drive to consolidate ranges. Lewis admitted that in some large stores as many as 20% of products were selling one unit or less a week.

The move to cut opening hours in the UK echoes a similar move by Tesco Ireland last year.

“We’re always thinking about how to best serve customers in each of our stores,” said a Tesco spokeswoman. “Where there is a case to look at the opening hours of a store, we will do so, but any decisions will be made locally and our colleagues will be the first to know.”