Marks & Spencer has delivered a policy U-turn of supporting check-out staff who refused to serve customers alcohol and pork products.

Thousands of furious customers threatened to boycott its stores after accusing the retailer of creating “division” in communities.

M&S said in a statement, “We regret that in the highlighted case this was not delivered to our usual standards. We would like to apologise for any resulting confusion and reassure our customers that this was an isolated incident.”

“Requests are considered on a case by case basis and may lead to an individual working in a department where conflicts wouldn‘t arise, such as in clothing or bakery in foods.”

M&S customer Ian Jones wrote on the retailers Facebook wall: “No sane shop would ever employ someone who made unsolicited criticism of a customer‘s purchases to, or in front of the customer… Although this kind of thing isn‘t yet happening in M & S in my Somerset town I for one will now boycott it while you continue to defend your policy of appeasing malicious stupidity that is offensive and discriminatory toward those of your customers.”

Dionne Barrington said: “You‘re not getting my cash. I‘ll shop at Sainsbury‘s and Tesco instead, where they don‘t employ people who refuse to serve their customers with their produce.”

M&S, whose Simply Food business now accounts for 34 per cent of total food sales, posted a disappointing general merchandise sales slip of -1.5 per cent over the 26 weeks to September 28.