Scarcely a week goes by it seems without another worrying development for the non-supermarket sectors of the trade.

Multiple stories of the top retailers tightening their grip on the convenience store sector do not make good reading for producers, wholesalers or the independent retailers that have survived the cull to this point.

The signs have been there for a while. Tesco acquired T&S in 2002, which was a pretty good indication of its intentions, and all bar Asda have made a move of some description deeper into the C-store marketplace in recent times.

No-one should be surprised by all this. After all, the role of the plc is to explore every money-making avenue to maximise returns to its shareholders.

But there does appear to be good cause for concern. Supermarket sales are by no means static at the top end of the scale, but the overall share of the market held by the major players is no longer increasing at the same rate they have become used to. It is time to look elsewhere for pickings, and the C-store route is an obvious contender.

The existing multiple-run C-stores have proved their worth to local communities, and as they do not depend on price-cutting to draw in customers, should be viewed as reasonable competition in most cases. However, the more their chains expand, the narrower the gap between pricing strategies in larger and smaller stores will become.

For fruit and vegetable traders, the threat is very real and the Office of Fair Trading must keep a very close eye on developments as they unfold.