"We've got hundreds of producers lined up who are literally packed and ready to come to Melbourne," she said.

Ms Sharp said pictures circulated on social media last weekend that appeared to show large crowds at a market were not taken at an accredited event.

She said the decision would force people to shop at supermarkets instead.

"While supermarkets are allowed to be open, we haven't even had a case [of coronavirus]," she said.

Farmers' markets introduced new safety standards under COVID-19 restrictions, including controlling shopper numbers and asking customers not to touch produce before buying it.

The markets have been trading across the state throughout the pandemic, but late this week they were removed quietly from the list of permitted industries under stage four restrictions, sparking confusion among organisers.

Victorian Farmers' Markets Association executive officer Kate Archdeacon said most of the network’s 36 accredited markets had remained open in Melbourne and regional Victoria during the latest round of restrictions.

Ms Archdeacon was seeking urgent clarification from the Department of Health and Human Services on Friday night. The Age has sought comment from the department.

“This is going to wipe out trading places for at least 300 producers without warning,” she said. “The impact across the sector is going to be huge.”

There were five accredited farmers' markets planned for Melbourne this weekend.

Ms Archdeacon said many customers wanted to shop in the open air rather than going to supermarkets. They also wanted to support local producers, who relied on the markets for their livelihoods.

“There are so many people who want to buy food this way,” she said. “As the markets have adapted [to coronavirus restrictions] we’ve seen more people go to some of them because that’s where they feel safe.”

Ms Archdeacon said that in some cases, markets had closed because schools and local councils decided they should not operate on their sites during the restrictions.

Apple and pear grower Heather Pollard said farmers' markets had been a saviour for the business.

She and husband Gary grow the fruit on their property in Elphinstone and they sell their produce at markets in regional Victoria and Melbourne.

Farmers' markets will still be allowed to operate in regional Victoria, which is under stage three restrictions.

Ms Pollard said some producers who had lost business with restaurants were now relying much more heavily on farmers' markets.

A weekly Bendigo farmers' market started operating in March and has continued ever since. There were previously bimonthly and monthly accredited farmers' markets in the city, but since the first round of COVID-19 restrictions they have added the weekly Thursday market.

Miramonte Farm owner Sue Jones, who sells beef from her Strathbogie farm, said farmers' markets accounted for about 90 per cent of her business.

She sells at markets in both Melbourne and regional Victoria.

“We rely on it,” she said. “During COVID, the markets we go to have become stronger because there are more people discovering farmers' markets.”

Seafood seller John Davidson said the markets had been a lifeline.

“There are a lot of smaller producers who just can’t get into major retail outlets like Coles, Woolworths and IGA,” he said. “Without these markets we would be close to being out of business.”

Some producers, including Newland-based vegetable grower Sandor Istella, have started selling produce from other farmers alongside their own.

At the Thursday Bendigo market, he has been selling about 50 boxes packed with vegetables and fruit, helping to keep his business alive. “It’s crucial,” he said.