As a consequence, Tesco, Britain's biggest supermarket chain, has asked its suppliers to grow smaller melons after focus groups of shoppers revealed that shoppers subconsciously selected fruit according to the trend in breast size.

After investigating a marked drop in melon sales, a retail psychologist's report for Tesco suggested that the modern preference for smaller breasts, as modelled by the likes of the superwaif Kate Moss, is informing customers' decisions to reject larger melons.

The company has instructed growers in Spain to produce galia melons of no more than 0.55kg, rather than the 1kg melons that were proving slow to sell.

A Tesco spokesman yesterday said the findings surprised him but insisted that the sales results spoke for themselves.

'Since we introduced the smaller melons two months ago we have sold more than a million.'

The possibility of a subconscious relationship between breast and melon size was first raised by a member of an all-female focus group, set up when Tesco buyers sought to find out why customers consistently picked the smallest fruit from store displays.

The theory was then tested by the retail psychologist, who found that seven out of 10 women questioned agreed that breast size was 'the most likely subconscious factor when selecting size of melon'. Half of the women went further, attesting that breast size was a conscious thought when choosing melons.

Most of the women believed that the modern obsession with small-breasted models made it more 'comforting' to choose smaller melons. Gender proved irrelevant to the subconscious influence: an all-male focus group produced similar results.

The report also noted that customers liked to feel around the 'blossom end', the nipple-like scar where the flower fell off during growth claiming that the relative softness of this part of the melon proved a good indicator of ripeness.