Sainsbury's has apologised after one of its checkout assistants refused to serve a shopper while she was on her mobile phone.
Jo Clarke, a 26-year-old property manager, said she reached the front of the queue at Sainsbury's in Crayford, south east London, when the assistant told her to end her phone conversation.
Miss Clarke said: "I was standing at the foot of the till waiting to bag my shopping up, yet the lady on the checkout was just staring at me, when I stopped my conversation and said 'Is everything OK?'.
"'She said 'I will not check your shopping out until you get off your mobile phone'.
"I ended my call swiftly and said to the lady on the checkout 'Apologies, I didn't realise that it was Sainsbury's policy that you are unable to use your phone at the checkout', and she said 'Well, you learn something new every day'."
Miss Clarke, from Crayford, said she checked with the customer service desk on her way out of the store on June 24, and was told it was not company policy.
The assistant has received support from some who have read about her stance.
Miss Clarke said she was "dumbfounded" by the checkout assistant's words.
"I don't know what she was playing at. I couldn't believe how rude she was. When did she have the right to give me a lecture on checkout etiquette?
"I won't be shopping there again, I'll go to Waitrose in Dartford instead," she said.
A Sainsbury's spokeswoman said: ""We have apologised to Ms Clarke. It isn't our policy to not serve customers who are using a mobile phone."