They joined Slow Food Hunter Valley Earth Market Maitland chairwoman Amorelle Dempster and Maitland Greens party member Jan Davis in speaking out about the plan at the city's first Genetically Modified Food forum on Thursday.

The impact on small farmers - especially those who have been using heritage seeds for generations and saving their best seeds for next year's crop, was a major issue.

Oakhampton vegetable farmer Austin Breiner said farmers used the principles of 'natural selection' every time they collected the seeds of their best performing plants.

In his opinion small farmers don't need a company to manufacture Genetically Modified seeds - the farmers themselves are already doing that for themselves.

Matthew Dennis, a vegetable farmer in East Maitland, echoed those calls and spoke about how his family have been collecting their best seeds for generations.

Ms Davis said everybody had to take steps to help stop deregulation taking place.

Ms Dempster said Slow Food Australia, and Slow Food International backed Slow Food Hunter Valley's position on the issue.

"We've had the deregulation of the banking, the Murray Darling Basin deregulated, we've had education deregulated, building and construction deregulation and look where it has got us. All of those aspects of our lives have been affected through deregulation and we have seen the corruption that has come from it," she said.

"We cannot trust big business to look after consumers and to think about the needs and the health of consumers - they are only interested in profit."

Ms Dempster collected signatures which will be sent with a letter to Paterson MP Meryl Swanson and Shadow Health Minister Chris Bowen. The letter urges them to put forward the city's concerns to their party colleagues and urge senators to vote against the plan.

"This is a very important issue and Meryl is aware of the importance of small-scale agriculture and how that has led to economic gains for the community here and also how it has kept families on family farms," Ms Dempster said.

"She knows the background and how important it is to our community - she was there when we sold Matt Dennis' pumpkins in The Levee back in 2016.

"We want good, clean and fair food for our community and we have demonstrated that this is possible. We don't want anybody putting unregulated gene technology onto our food system that can affect our small-scale farmers and our health."