This change will affect around 3,500 workers, who are set to transfer to one of two external companies. David Lepley, chief operating officer at Asda, said: "Our ambition is to deliver the cleanest stores in retail. Asda said customers will see improvements such as cleaner toilets, steam-cleaned trolleys and baskets, and greater use of robotic cleaning equipment. "Now loyal, hard-working cleaning staff will be worried sick about whether their job will still pay the bills or whether the axe will fall on them. The union also said it asked Asda in April if more outsourcing was planned and was told there was not.