Retailer Co-op is to offer its members £10 off a minimum shop of £40 following disruption caused by a recent cyber attack.

The grocery chain said it had not yet completely recovered from being targeted by hackers last month, which resulted in a significant amount of customer data being stolen.

Although the offer appears generous, one analysts said the majority of customers do not spend £40 or more per shop, so it would not appeal to many people.

The one-off deal, which runs from Wednesday for a week, is open to existing Co-op members, and a shoppers wanting to sign up, but not to staff.

A Co-op source said since stock levels had returned to normal over the past few weeks, there had been a strong pick-up in sales.

The offer was to show that the Co-op was "on the front foot" ahead of summer trading, the source told the BBC.

But retail consultant Catherine Shuttleworth said the offer indicated that members may have started to shop elsewhere and was an effort from Co-op to try to get them back.

Co-op said if members spend £40 or more in store, they will get £10 off their shop.

"You'd be pushed to spend that in a Co-op - the average shop would be between £10 and £15. It's a very high threshold for a convenience business," added Ms Shuttleworth.

She said the chain was trying to show commitment to its frequent shoppers, but suggested the business was "not going to be huge redemptions on that offer".

Ms Shuttleworth said members would probably appreciate practical help on securing their data more.

In some rural areas such as Skye in Scotland, the Co-op is the main shop - albeit with a choice of other smaller retailers.

But the majority of Co-op stores are in urban areas with more competition.

The retailer said it was "very near to making a full and complete recovery" from the recent cyber attack and added its 2,300 stores were returning to usual trading.

During the attack, which came to light in May, hackers got into Co-op's technology networks and stole past and present member data.

The retailer shut down its systems to restrict the damage, and managed to continue to trade, but there is still some behind-the-scenes disruption, the source said.

Customers complained of empty shelves as the incident disrupted deliveries of fresh stock.

Co-op said its offer was a "gesture of appreciation" to its 6.5 million members.

The BBC understands that Co-op is not planning to offer any fraud prevention or identity monitoring.

Ms Shuttleworth estimated that the cyber-attack would have cost Co-op "millions of pounds" in lost sales.

She said the offer was "a call to customers to come back", and for Co-op to show that it was open for business.

"If you can't manage to get what you want, you go elsewhere," she added.