Australia plans to lure more than 10,000 farm workers from Southeast Asia under a new agriculture visa farmers have long campaigned for.
Industry calls for the dedicated category had been rebuffed for years despite the Nationals pushing for it from within coalition.
Australia overnight agreed with the UK to scrap the requirement for British backpackers to do an 88-day work stint in regional areas before extending their working holidays.
That has prompted the government to abandon its opposition to the visa.
Nationals leader Michael McCormack, who is acting prime minister while Scott Morrison is in the UK, has promised to deliver it within three months.
The visa will allow people from the 10 Association of Southeast Asian Nations and the UK to work on Australian farms for three years.
They will need to return home for three months each year.
Agriculture Minister David Littleproud said the plan involved more than 10,000 places as a baseline to cover the shortfall in backpackers.
"Unfortunately Australians can't be incentivised to go and have a crack at these jobs. We've got to be honest about that," he told ABC radio on Wednesday.
Australia's fruit and vegetable growers needed and estimated 26,000 workers to harvest crops last summer.
A union survey of 1300 seasonal workers found 78 per cent were underpaid with some earning as little as $9 a day.
But Mr Littleproud insists bad apples among employers are a minority with conditions almost always up to award standards.
"Anyone that doesn't, needs to be found out and weeded out - they're a cancer," he said.
"It's dangerous where you've got unions running around and demonising farmers broadly when that's not the case."
Australian Workers Union secretary Daniel Walton described the move as shameless, stupid and immoral.
"Scott Morrison and Boris Johnson have decided it's wrong for Brits to be exposed to exploitation and abuse on Australian farms, but apparently it's OK for Southeast Asians," he said.
He said the minister's claims Australians were not motivated to do the jobs were "absolute garbage".
"They can be incentivised to do those jobs with decent pay and conditions that protect them from abuse," Mr Walton said.
"If the government goes ahead with this abhorrent proposal exploitation and abuse on Australian farms will explode."
Mr Morrison backed an agriculture visa in 2018 but later said the expansion of existing migration programs meant there was no longer a need for a dedicated category.
"That is something I've had a positive view on for some time," Mr Morrison told reporters in London.
Victorian Farmers Federation vice-president Emma Germano, who has long pushed for the visa, said it was needed for horticulture, as well as other skilled and unskilled jobs in other sectors.
"From milkers, livestock farm hands, pickers, packers, machinery drivers; everyone is having trouble finding labour," she said.
"Right now we need smart policy solutions for a wicked human capital problem and I hope this decision opens the door to a resolution."
Australian Associated Press