They say manners cost nothing, but Sainsbury's ended up out of pocket this week after a customer complained that a checkout assistant had refused to serve her while she was on her mobile phone. STACIA BRIGGS asks whether we're too hung up on phone etiquette.

Depending on your perspective, it was either a clarion call for modern manners or a blow for personal freedom – should checkout assistants have the right not to serve you if you're using your phone?

At a supermarket in south east London, property manager Jo Clarke, 26, was furious when she was told by the checkout assistant that her goods wouldn't be scanned unless she hung up.

Sainsbury's was forced to apologise to Ms Clarke, who complained to the manager after the incident last week, and offered her a £10 voucher to compensate her for her treatment.

'I don't know what she was playing at. I couldn't believe how rude she was,' said Ms Clarke. '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, instead.'

But users of internet forums and social media sites were inflamed by the store's climb-down, with the vast majority firmly nailing their colours to the mast and siding with the assistant.

They included: 'Well done to the checkout girl. Everywhere you go these days you have to listen to people telling everyone else their private business as full volume. I wouldn't answer my phone at all if I was at a checkout or being served by anyone, it's just plain ignorant.'

Many were summed up by the succinct: 'The customer is not always right!'

Others pointed out that it was not just customers who forget their manners while at the till. Shop assistants have also been known to carry on conversations – on the phone or to a colleague – while totally ignoring those they are supposed to be serving.

On our website www.edp24.co.uk, one commenter said: 'It is phenomenally rude not to look up at someone when you are talking to them, especially if they are a customer.

'Some staff don't even look up and even continue a conversation with other staff. Those in smaller businesses who answer phones while dealing with my inquiry or purchase are likely to lose my custom.'

While Sainsbury's – which launched its own mobile phone business this week – doesn't have an official policy about not serving people who are on mobile phones, other businesses do.

Last year, Darren Groom, who runs Little Red Roaster on Grove Road, in Norwich, and has had a coffee stall on Norwich market for more than a decade, caused a stir by refusing to serve customers who were talking on their mobile phones.

His poster which he pinned up at the stall and which read: 'We are unable to serve you coffee if you are on the phone' made headlines across the globe and sparked an international debate about etiquette.

'It all went quite mad last year when, in fact, it wasn't so much about mobile phones but rather about creating a better experience for our customers,' he said.

'We still have people who come to the stall now and pretend to be on their phones when they order to tease me, which is great, but I always worry that I might look like a hypocrite because there are times when I absolutely have to be on my phone at work.

'I always try and get off quickly before I serve the customer but occasionally it's unavoidable. My belief remains that, unless a call is essential, if it's just chit-chat, it's rude to stay on the phone whether you're a customer or serving a customer.

'I'd suggest that it's always a better experience if you're both dealing with each other, rather than with a call on a phone.'

Alan George is a hospitality lecturer and runs the training restaurant, Debut, at City College Norwich.

At the beginning of next term, he will be banning students from bringing mobile phones into their training sessions ('I can imagine there may be a few battles!' he laughed).

'I have the very explicit view that it's incredibly rude when you are engaging with someone to be using your mobile phone, particularly in a day and age when there is so much criticism about customer service,' he said.

'In my commercial life, before I went into teaching, I did have occasion to go to a customer's table and say that I was really sorry, but would appreciate them taking their calls outside. They weren't happy about it, but you have to remain professional and your duty is to all your customers and to make sure their experience is a good one.'

Mr George said that although he sympathised with the checkout assistant, he would have advised a different approach to the customer which might have defused the situation. 'I might have said: 'I am really sorry, but I can't process your transaction until I can engage with you fully'. Something non-confrontational but which gets the point across.'

He added: 'Some students, worried at the potential loss of their mobile phones for a few hours from September, have said to me: 'but what if my parents need to get hold of me? What if my girlfriend or boyfriend needs to speak to me?'

'I've told them that there are these old-fashioned things called landlines on reception and that any urgent messages can reach them that way. I'm not entirely sure they believe me!'

How well-mannered do you think you are? Take our test at www.edp24.co.uk/news/manners-quiz