Somerset-based Middlebrook mushrooms, the largest supermarket supplier of mushrooms, is claiming it is discriminatory to make mushroom growers in Britain pay higher rates to their pickers than those working for other vegetable producers.

The supplier is seeking a judicial review of the decision by the Agricultural Wages Board to exempt mushroom growers from a minimum permitted pay rate of £4.50 an hour for harvest workers.

Middlebrook’s challenge is being backed by other growers in the industry.