Stephen Jardine: Aggressive price comparison policy a good reason to check out of supermarket

My brave sortie followed the experience of a Guardian journalist who went to a London branch of Tesco and entered a Kafkaesque nightmare. Having been spotted by security cameras, a deputy manager approached and asked what he was doing.

The writer explained he was shopping and comparing prices but apparently, that is not allowed. “It’s illegal to write things down and you can’t take any photographs either. If you want to check the prices, take the item to the till and pay for it there. The price will be on the receipt”, the employee is quoted as saying. The store manager then arrived on the scene and backed his deputy. “It’s company policy. You’re not allowed to do it”.

Anxious to finish his shopping and escape the Spanish Inquisition, the journalist agreed to put his notebook away and compare prices only with his eyes. The bizarre incident led to an avalanche of criticism for the High Street giant and the company has since publicly distanced itself from what was said.

Thankfully, my visit to a Tesco store in Edinburgh passed incident free. The Scotsman notebook and pen provoked barely a glance from the staff who seemed too busy filling shelves to bother themselves with commercial espionage.

But the whole story raises some serious issues. Tesco’s size and scale has been a concern for some time and rightly so as evidenced by the arrogance displayed in this incident. Tesco may sell food, flowers, petrol, insurance, mobile phones, contact lenses and even garden sheds but it isn’t yet making the law of the land. Some members of staff clearly believe that is only a matter of time. But the sensitivity does give a rare insight into something else. What Tesco and the others supermarkets fear is a light being shone into the murky world of pricing and special offers and the timing of all this is no coincidence.

Tesco has just launched its Big Price Drop promotion. On offer, a range of groceries including packs of meatballs, which are normally £4 each. For a limited time only you can buy three – be still my beating, cholesterol-clogged heart – for just a tenner. Anyone attracted by 72 meatballs needs a psychiatrist not a supermarket.

Trying to compare like with like is almost as tough as the meatball mountain challenge. Tesco sells its flat leaf parsley in 30g bags, Sainsbury’s prefer 28g bags and Asda go for 25g bags which makes it very hard to work out any genuine value. Funny that.

Very few of us have the time – never mind the inclination – to trawl the supermarkets, noting prices and contrasting packaging. Instead, the average family shop is a trolley dash punctuated by not being able to find things and a nagging sense at the end that it cost more than you’d expected.

The supermarkets rely on our ignorance of how much things cost and then confuse us with special offer promotions which are fleeting and complex. That’s why someone with a notepad and dogged determination appears so dangerous.

In reality, there is no escape from what they offer. Most people juggling work and family life have to rely on the supermarkets for convenience, parking and the sheer speed of a large shopping experience. But in the headlong race for greater market share and profitability, some worrying developments are taking place.

Juggling prices to confuse the consumer may be a commercial reality in a competitive marketplace. But threatening individuals who seek to lift the lid on that is a price that is never worth paying.