Or is it? The grocery supply chain is generally thought to be a fairly free and fluid thing. You can more or less buy your baked beans from anybody. The government hasn’t had to intervene the way it did with banks to make it easier for you to shop around and move your account. Or the way it did with newspaper distributors to make supplies more readily available to willing outlets.

Yet it sometimes throws up the very odd hiccup. Huw Griffiths wants to switch suppliers but is finding it very difficult. Huw has two sites: Petrostore, which trades at Brigend, and Llantwit Main Service Station, being rebuilt at Cross Ninn near Ponty Clun. Both sites were supplied by Costcutter although the one being rebuilt at Cross Ninn was flattened 18 months ago to make way for a new 5,000sq ft development so his contract with Costcutter for supplies to that site is long finished.

While preparing for its reopening Huw shopped around and decided that Nisa-Today’s offered him a better deal so he has signed up with the group.

At Brigend,10 miles away, Huw is still being serviced by Costcutter. He decided it would be best to put both stores into the Nisa-Today’s group but was shocked to be told that there would be effectively two six-month periods of notice to serve. He had to give Costcutter six months notice, as per contract, and then Nisa would not touch him for another six months because, he was told, of a ‘gentleman’s agreement’ between the two.

One can understand the six months required as notice to one’s existing supplier, but the second stage? What’s he supposed to do? Trawl round the cash and carry for half a year? Huw says: “We need to buy very carefully for our stores. At Brigend, alcohol and car wash are the most important profit centres. At our margins every percentage point counts and I would save money by joining Nisa-Today’s.”

As far as he is concerned, neither of his sites sport either Nisa-Today’s nor Costcutter’s branding so it is simply a supply deal. I did attempt to discuss this story with Nisa-Today’s, which was both in the middle of disbanding its Central Buying Company and holding its annual conference in Portugal, but after six telephone conversations over a fortnight with various people I was eventually referred back to Costcutter which robustly refutes that Huw will save any money by switching.

But nevertheless shouldn’t it be up to him? In these trying times of mergers and acquisitions and shrinking markets obviously Nisa needs to keep its biggest customer happy (and Costcutter represents 43 per cent of Nisa’s distribution) but would switching just one site make much difference in the great scheme of things