The Liberals and The Nationals split when the legislation was initially passed in the House – the former voting with the Government – in a game that has ultimately cost wheat growers, Mr Windsor said.

“It’s a fairly sad event. It’s about politics between the Libs and the Nats,” he said.

But Labor was in no position to celebrate according to Mr Windsor, who said they had ignored what farmers wanted and had broken a promise, along with the previous government. The Leader asked Mr Windsor if democracy had failed these farmers, to which he replied: “Very much so”.

“Both sides of parliament said they would poll wheat growers and neither did,” he said.

“Rudd said he would do it and when Howard was considering changes 18 months ago he said he would too, but neither did.”

NSW grower Jock Munro, who was at the forefront of protests, said the new system would see the volume of wheat grown each year halved to 10 million tonnes within three years.

“This is the most lethal, disgusting piece of legislation you’ll ever see,” he said.

“It’s the blackest day for Australian agriculture.”

Mr Windsor said it was hard to tell what effect abolishing the single desk would have.

“I don’t know if wheat crops will halve – I wouldn’t like to guess – but people will base their decisions to grow different crops given the prices of the market,” he said.

“People will never know whether they will be better or worse off without the single desk but these farmers believed it was in their best interests.”

Agriculture Minister Tony Burke said the new scheme was a major economic reform that would at last give farmers the right to choose who exported their wheat.

He announced Wheat Exports Australia would be chaired by Ted Woodley, a former head of large grain and energy companies, including the NSW Grain Corporation.