Tesco boss Philip Clarke supposedly signalled the end of an era for cheap supermarket produce this weekend, as a poll claimed 80% of Brits would be prepared to pay more for our food if it benefitted domestic farmers.

Far be it from me to cast doubt on these two claims, or suggest the sun has gone to a few people’s heads, but I will leave it to Defra and the Daily Mail to bring a dose of reality.

While it was interesting to read Clarke acknowledge that the laws of supply and demand will inevitably kick in to put upward pressure on prices unless the food chain becomes more sustainable, the headlines around his comments to food writer Jay Rayner in The Observer need to be taken with a celebrity chef-sized dose of salt.

Last week a report produced on behalf of Defra on the back of its Green Food project came to the conclusion that consumers were in fact ever more motivated by price and volume, with the lure of supermarket discounts such as multibuys stronger than ever. The sustainability of their diets, it argued, took a very clear back seat.

With this in mind, scepticism would be also be well advised around the poll – produced for the Prince’s Countryside Fund by YouGov to draw attention to National Countryside Week, starting today – which found four-fifths would happily pay more if it benefitted our farmers.

Retailers don’t need a study from Defra to know that the last thing most consumers really want are higher food prices, whatever the environmental issues at stake; and Tesco didn’t invest millions in its Price Promise this year in a bid to persuade shoppers to consider paying more for food, however much passion for it they may have.

And ‘passion for food’, incidentally, is something the supermarket is trying to play up in its latest ad campaign. ‘Love Every Mouthful’, launched on Sunday, is the brainchild of Tesco’s new ad agency W+K, and seeks to align the retailer with the “national obsession with food”. W+K goes by the motto ‘Welcome to Optimism’, but it might be too optimistic even for them to expect consumers to start paying more for their food, whatever the arguments in favour.

If you are in any doubt, then simply pay heed to the other Tesco headline this weekend, which was to be found in the Mail on Sunday. It screamed of outrage at the 40% price hike for Tesco’s budget bottled water, which was all too much for the sun-bashed British, forced to pay a staggering 24p for two litres of the stuff, up from 17p.

If that was enough to leave Tesco accused of “shameless profiteering”, what will the headlines be if Clarke really does start putting up prices?