Anti-pesticide groups say banning the insecticide, endosulfan would give New Zealand-grown tomatoes a marketing advantage over imports from Australia.
The Environmental Risk management Authority is reviewing the use of endosulfan to control insect pests on crops, but is allowing its continued use in the meantime.
The Pesticide Action Network and the Soil and Health Association want New Zealand to join 55 other countries in banning the chemical, which they describe as highly toxic and persistent, and the worst pesticide still used in New Zealand.
Soil and Health Association spokesman Steffan Browning says independent testing has found endosulfan residues in both New Zealand and Australian tomatoes.
But he says the residues were 4½ times higher in the sample of Australian cherry tomatoes than in the New Zealand product, and local growers could use that to their advantage.
