Queuing could become a thing of the past at Sainsbury's in Burton and Swadlincote - sparking fears for the future of jobs at stores across the supermarket's UK network.

Sainsbury's is looking to introduce a new app allowing shoppers to pay for items on their phones, it has been revealed. But shop workers' union Usdaw is concerned the move could lead to staffing cutbacks.

Under the new system, shoppers will be able to scan products on their phones and the cost of the goods will then be deducted directly from their bank account. Once the payment has been made, customers can leave the store.

The supermarket, which has stores in Burton and Swadlincote, has tested a prototype of the checkout-free shopping at a store in London.

Head of customer experience at Sainsbury's Natalie Dunn said the site was picked to test the technology because its customers are usually in a rush to catch trains and were keen to get in and out as quickly as possible.

She said: "We are always looking for new ways to help our customers live well - and saving customers' time is one way we can do so.

The supermarket is looking at introducing an app to pay for shopping on your phone

"Experimenting with a checkout-free experience is a first for Sainsbury's and many of our customers, so we are keen to understand how we can take the concept and develop an offering that is genuinely useful for those who shop with us. We are very excited to have taken this first step."

But Usdaw, the shop workers' union, said it feared the technology could have implications for the supermarket's workforce.

Usdaw spokesman David Williams said: "We know that many customers really value one to one personal interaction they receive from shop workers and there has been much research showing that often it is quicker to go through a staffed checkout.

"Reduced staffing can cause customer frustration and it is generally shop workers who bear the brunt of any resulting abuse."

During the September trials customers used an app on their phone to buy the store's £3 meal deal, which consists of three items: a sandwich, side and a drink without having to queue to pay.

But to help those honest customers who feel guilty about leaving a store without stopping to pay, the company said it could look into a system where they have to scan a sensor or barcode to prove they have paid.

The supermarket said it has already received positive feedback from the trials but is yet to set out a timetable for when the checkout-free shopping will be rolled out in all its stores.

Although there will be a wait for the app, the company has already introduced ‘SmartShop’, a service where customers can scan their items using a handset or mobile phone as they shop and then pay at a checkout at the end, which will be in 50 stores by the end of the year.

The supermarket does not expect shoplifting to increase because of the new technology but said it would be looking into security measures as it continues to work on the app.

Looking for a job? There are thousands available at www.Fish4.co.uk