The peak body representing Australian vegetable growers has called Woolworths “churlish” and “belligerent” after the supermarket giant cancelled a meeting between farmers and international buyers in the wake of growing protests about a marketing campaign featuring celebrity chef Jamie Oliver.

Ausveg appealed to Oliver to step in after Woolworths imposed a levy of 40 cents a crate on growers to pay for a major advertising campaign that carries his endorsement.

Following a public backlash that saw consumers supporting farmers in the appeal, Ausveg chief executive Richard Mulcahy said Woolworths had rescinded on a longstanding commitment to allow international buyers from crucial Asian export markets to visit a distribution centre in Sydney.

“This churlish action by Woolworths is not in the national interest given that both industry and the Australian government have identified expanding export markets as a crucial priority for the future growth of our industry,” Mulcahy said.

“My staff received a call from a government relations executive at Woolworths [Thursday] morning informing us the relevant people are ‘no longer available’ for the visit to the distribution centre next week.

“Woolworths are certainly not winning friends in the Australian vegetable industry, nor with customers by taking such a belligerent attitude on matters of such critical importance to our nation.”

For some growers, the additional money expected to take part in Woolworth’s advertising campaign featuring Oliver amounts to hundreds of thousands of dollars, Ausveg spokesman William Churchill says.

He said Oliver’s “people” have said they are aware of the situation, but have made no further response. It has prompted Ausveg to repeat their calls to Oliver to use his influence to intervene and encourage Woolworths to refund Australian growers.

Neither Woolworths nor Oliver have responded to requests from the Guardian Australia for comment.