The NFU has flagged up the opportunity for growers to supply the wholesalers as part of its management of the capital's wholesale markets' business development manager scheme.
The programme aims to link fresh produce growers with opportunities in the London wholesale markets.
Four of the wholesalers at Western International have vegetable preparation factories where they peel, slice and process fresh produce.
Much of this prepared vegetable is then sold to food service outlets and food manufacturers.
An NFU representative said: "Supplying produce to these factories is a good opportunity for UK growers. Often they can take sizes that are hard to sell in the retail sector, or produce with skin blemishes that will be removed when they are peeled."
Produce required for this market includes aubergines, cucumbers, peppers, broccoli, garlic, potatoes, spinach, cabbage and horseradish. Also sought are tomatoes, carrots, salad and ware onions, cauliflowers, courgettes and parsnips.
Growers interested in this potential market can call Peter Clarke on 07947 764995 or email pclarke firstname.lastname@example.org.