The council became the first in New Zealand to secure the territory's GM-free food producer status under the local plan.
"The response has been great and we are very humbled by the generosity of the Hawke's Bay community who believe in a GM-free region," Mr McFarlane said.
"But we have a long way to go and we are encouraging the people of Hastings to get in behind us."
He said Pure HB was confident the district's valuable GM-free status could be secured in law, but wider financial support was crucial to building a strong case to win this legal battle.
This weekend, the campaign team spent hours banging up billboards around the city.
"We spent the weekend putting up signs around the city and received a really positive response in Hastings," Mr MacFarlane said. "As we are getting the message out there, people are recognising that it's important to support the fight to keep Hastings GM free.
"Hastings people understand that preserving our GM-free status will benefit everyone, not just food producers."