An environmental group in Marlborough is angry that authorities have allowed an exporter to resume using a toxic chemical to fumigate a shipment of logs at Shakespeare Bay in Picton.
Following an outcry over the health effects of methyl bromide, the ozone-depleting gas has been used only once since 2007 at Shakespeare Bay.
Peter Beech, who chairs the group Guardian of the Sounds, says that when the gas was used in February, it was understood to be a one-off.
He says hundreds of anti-fumigation bumper stickers and leaflets will be distributed to Picton residents and tourists next week, so people know they are in what he calls a toxic town.
Rick Osborne from the log exporting company Zindia, which is handling the fumigation, says India requires the chemical treatment by law.
Mr Osborne says fumigations are subject to stringent safety monitoring and he does not think the environmental group's protest stance is warranted.
He says technology such as gas-capture systems could be years away from being introduced in Picton.
Marlborough Mayor Alistair Sowman says the environmental group's actions will not end fumigation at Picton but will damage the area's reputation nationally and potentially internationally.
He described the protesters as a small group that has gone "completely over the top".