An Irish member of the European parliament has complained that supermarket chains maintain "a very strong armlock" on fruit and vegetable growers, and is calling for an investigation.

Mairead McGuinness, who represents the Leinster constituency - centre of much of the Irish horticulture industry - is asking the European Commission to ensure growers get "a fair return" for their produce.

"Producers are often simply price-takers, with prices often bearing no real relationship to what the consumer actually pays.

"The main issue at stake here is the concentration of power in the hands of a few major supermarkets, and the challenge for the Commission is whether it is prepared to address that."

Four producers have been forced to quit in recent months. Patrick Jones, at the Irish Farmers Association said grower profit on an acre of winter cabbage was just €8.

The industry would ­disappear unless growers' prices improved, he claimed.