And so it begins.

Amazon, the world-dominating online retailer, is to roll out its Amazon Go self-service store format to U.K. high streets.

The first is to be near London's Oxford Street with other cities including Manchester and Birmingham set to follow with requirements for 4K to 5K SF units, Retail Gazette and the Sunday Telegraph report.

Cashierless Amazon Go was launched on the U.S. West Coast earlier this year. The automated store chain is expected to grow to 3,000 outlets by 2021.

The latest reports may be more reliable than suggestions that Amazon was eyeing either ex-Homebase stores or the surplus stores released by the proposed Sainsbury/Asda merger.

In November stories emerged that Amazon was “eyeing” supermarkets that Asda and Sainsbury’s might be forced to give up if they are allowed to merge. The acquisitions would expand its own grocery business, Amazon Fresh, and the rumors were based on its submission to the Competition and Markets Authority’s investigation of the merger.

However, analysis by Bisnow of the Competition and Marks Authority documentation suggested that the arrival of Amazon's Whole Foods or Fresh fascia in big-box retail might be delayed or a non-event.

“Amazon indicated that they always keep options under review in relation to investments and acquisitions in relation to both the groceries segment and other market segments in the U.K.,” the CMA said in its report of the conversation with Amazon.