A Morrisons supermarket is seen in south London, Britain August 19, 2016. REUTERS/Peter Nicholls/File Photo

US online retailer Amazon and British supermarket group Morrisons are extending their “Morrisons at Amazon” same-day online grocery delivery service to more cities across Britain.

The service, currently available to Amazon’s Prime Now customers in Leeds, Manchester, Birmingham and parts of London, will be rolled out to Glasgow, Newcastle, Liverpool, Sheffield and Portsmouth this year, the companies said on Thursday (13 June).

It allows Amazon Prime customers to order a full Morrisons shop online, which is then picked at a local store, and delivered by Amazon, with an option for delivery within one hour of the order being placed in some locations.

The service will be expanded to more British cities in future, the companies said.

Morrisons, Britain’s fourth-biggest supermarket group behind Walmart’s Asda, Sainsbury’s and market leader Tesco, also provides food in a wholesale deal for Amazon’s “Fresh” and “Pantry” grocery offers.

The US online giant has gradually extended its food offer in Britain, but according to market researchers Kantar Worldpanel, its market share is still less than 1%.