When Sian Jarvis appeared on yesterday’s Radio 4 ‘Today’ programme to chat through Asda’s work towards the Responsibility Deal with presenter James Naughtie, it’s safe to say things didn’t quite go as planned for the Asda corporate affairs chief.

Jarvis, former spin doctor at the Department of Health, began by highlighting Asda’s comprehensive (and industry-leading) hybrid labelling, which has provided traffic lights, guideline daily allowances, and low, medium and high indicators for the past five years. She added that Asda was looking forward to sharing the detailed research it had built up over those five years with the government as it looks to roll out a similar scheme by next summer (possibly ambitious, given the progress supermarkets, suppliers and the government have made towards establishing a groceries code adjudicator).

Jarvis went on to call for manufacturers to stop worrying that a red light might “demonise” their products and said that customers were far cleverer than often given credit for.

So far, so good.

Then Naughtie bought up the hoary old debate over confectionery racks at checkouts tempting children with chocolate and sweets, conjuring up images of poor stressed-out mums browbeaten into buying a Milky Way for a wailing five-year-old. Naughtie bought up the Children’s Food Campaign, which, hands-a-wringing, has apparently described Asda as “just about bottom of the heap” when it comes to offering “great displays of fattening and sugar-loaded confectionery to tempt at the checkout”.

“One in three of our checkouts are guilt-free,” replied Jarvis, fatally, and Naughtie smelled blood. “Two out of three are deliberately guilty, then,” he crowed, flipping the stat. “Guilt laden!”

Never mind that the same child will have just walked around thousands of square feet of shop floor offering everything from toys, t-shirts, milkshakes, hamburgers, DVDs, video games, crisps, biscuits and 100ft-long aisles stacked high with giant, big, medium, small and fun-sized bars of chocolate and hundreds of bags of sugary sweets. The real danger area, it emerges, is two shelves of chocolate at the till.

Naughtie dismissed Jarvis’s suggestion that “as retailers, we are not there to prevent people choosing what they want to buy”, then worked himself up into a rant about supermarkets designing stores to encourage purchases, culminating in a blast at Asda for “deliberately tempting people to buy things”. Naughty retailer.

Jarvis rallied, promoting Asda’s fresh meat and fish counters and its in-store bakeries, reminding Naughtie that Asda was the first supermarket to adopt hybrid food labelling to help customers make informed choices, was an early signatory of the Responsibility Deal, and that Asda was the first company to hit salt targets back in 2010.

It was straight back to the checkouts for Naughtie, though, and Jarvis reassured him that Asda would look at its tills as part of the Deal, although she added there was no evidence that mums bought any more confectionery as a result of tills being ‘guilty’.

Naughtie harrumphed a grudging thank you. And Jarvis left the studio to a blaze of headlines.

Jarvis will no doubt kick herself for using industry jargon like “guilt-free” to a radio presenter spoiling for a fight. But in this weekend’s Grocer we reveal that Asda has something up its sleeve that will demonstrate its commitment to nutritional labelling is sound.

And it’s a far more significant move than agonising over whether or not to let its customers rewards themselves by grabbing a cheeky Kit Kat to round off the weekly shop.