The Co-op is set to roll out technology that allows shoppers to scan and pay for items on their smartphone while they shop, and then walk out of the store without visiting a till.

The retailer’s “shop, scan and go” service follows Amazon’s experiment with an automated convenience store in the US. Such initiatives could spell the beginning of the end for the supermarket checkout – fuelling fears that automation could eventually eliminate millions of retail jobs. In Britain, 2.9 million people are employed in the retail trade.

A Co-op spokesman said the pay-in-the-aisle technology, a joint venture with Mastercard, would appeal to time-pressed shoppers looking for a fast, “frictionless” buying experience where they did not have to queue at the till.

The member-owned business is in the final stages of a trial at a store in its support centre in Manchester which is not open to the public. There is expected to be a further trial at the Co-op in Microsoft’s UK headquarters in Reading, Berkshire, but the store group said a wider rollout is expected to start as early as this summer.

In September 2017, Sainsbury’s revealed it was testing a similar app. However, that trial was limited to people buying a meal deal of three items at one store in central London. The Co-op said its service was believed to be a UK first for a supermarket because it covered all the products in its store, with no need to visit the till.

A number of retailers in the US have launched similar initiatives. Amazon’s automated grocery store in Seattle – branded Amazon Go – opened in January 2018. The same month Walmart announced it was expanding a trial of its Scan & Go app to another 100 stores across the country.

With the Co-op service, shoppers scan products with their phone as they walk around the store. When they have finished shopping, they can “check out” using their payment card details stored within the app, and then leave the store, with both the Co-op and the individual knowing they have paid.

The retailer said it was seeing a steep fall in the number of cash transactions in its stores as customers used alternative payment methods.

However, it insisted the new technology would complement, not replace, its existing ways of shopping and paying. Matthew Speight, the Co-op director of retail support, said: “It is all about consumer choices and convenience … We recognise there are many communities where customers pop in to their local Co-op and enjoy a friendly chat – it is all part of the service. Whereas for others, perhaps with a train to catch or on a school run, every second can count as consumers seek increased convenience.”

Some have wondered whether the rise of checkout-free technology could trigger an increase in shoplifting – while Sainsbury’s reportedly said of its trial that honest customers “feel uncomfortable just walking out”.