Changes will be made to the proposed Food Bill to ensure small traders and community groups are not tied up in "excessive red tape", says government minister and Nelson MP Nick Smith.

In an attempt to quell growing alarm over the bill, he said the legislation clearly needed more work and would not be rushed.

Submissions on the bill – whose main purpose is to ensure that the food people buy is safe to eat – closed in September. A Facebook petition that says the bill "will seriously impede initiatives like community gardens, food co-ops, heritage seed banks, farmers' markets, bake sales, and roadside fruit and vegetable stalls" had attracted more than 28,500 signatures by yesterday.

A viral internet campaign has seen many smaller growers bombarded with emails warning that the Government is trying to sneak through the bill, which the emails say has the potential to greatly restrict what they do and once passed will be impossible to change because it is tied to international agreements.

The NZ Food Security website claims the bill would make the sharing of seeds illegal, and that police could raid premises without a warrant, using guns if necessary.

Dr Smith acknowledged that there were concerns over the legislation, saying he had been approached by about 10 people and several local authorities.

"I'm keen to sit down with some of the groups concerned and clearly establish what are legitimate concerns and what are no more than conspiracy theories.

"I think some of the conspiracy theories about the bill being driven by multinational corporates who want to limit what food people eat is all a bit of a nonsense, but where we do need to be careful is that the regulatory system that is set up isn't too costly for small operators."

The bill, which would replace the outdated and cumbersome 1981 Food Act, needed to strike a balance between providing people with freedom of choice and ensuring they were safe, he said. It was also vital that it better protected New Zealand's reputation as a food exporter.

There was still some work to do to get the balance right – for example, deciding how big cottage industries such as cheesemakers needed to be before they required proper food safety systems, Dr Smith said.

Labour's primary industries spokesman Damien O'Connor, who is on the select committee considering the bill, said he had received a lot of emails from his West Coast-Tasman constituents concerned about its implications.

"There is quite a bit of misinformation out there, but that's the Government's job to clarify."

He said Labour would not support the bill unless areas were clarified, and he had asked the Government to detail what changes it was proposing.

"We need to ensure small traders and community groups are not clobbered by this bill, but there is a need for New Zealand to improve its behaviour around general commercial food and food handling."

He was concerned that the bill as it stood was using a "sledgehammer to crack a walnut" and would hinder the growth of farmers' markets and alternative food supply networks which needed to be supported.

"I'm concerned that the supermarkets don't control the food supply in New Zealand any more than they do now."

Nelson Farmers' Market manager Janet Whittington said stallholders were worried by the impact the bill could have on them, and the organisation was seeking legal and political clarification.

For example, it was unclear whether bartering was allowed under the bill if no food handling or safety plan was in place, she said. Even fundraising charities and home growers selling excess backyard produce were not exempt.

"There is potential to put ridiculous bureaucratic impediments in the way of those in the informal food sectors, such as our small local growers, producers and charities who are mostly selling and exchanging healthy foods like produce, plus the odd sausage, strudel or jar of jam."

Such requirements would force people supplying the market to raise their prices, Ms Whittington said.

Miles Gwynne, who runs an organic and heritage vegetable seedling nursery at Dovedale, said the classification of seeds and seedlings as food under the bill would put his business at risk and would force him to make major changes.

The one-size-fits-all approach adopted by the bill was short-sighted, and would reduce choice and lifestyle options and result in the "sanitisation of the creation of food", he said.