Earlier this month, a major report into Australia's agricultural labour crisis called for an amnesty — among other sweeping changes.
Nationals backbenchers support the idea and are set to push for it to become official party policy at its federal conference on Sunday.
But Liberal Cabinet minister Michaelia Cash said the government would not be budging on changing the status of "illegal migrant workers".
“This would undermine the integrity of this government's strong visa system and we are not going to do that,” she told a Senate estimates hearing.
“There will be no amnesty.”
Under questioning from Victorian Labor Senator Raff Ciccone, Home Affairs secretary Michael Pezzullo said he would recommend against the idea.
“It would not be our advice to change direction because of the perverse incentive to get to Australia, overstay your visa and then go to ground,” he said.
Mr Pezzullo also said the government never committed to a dedicated agriculture visa, despite Prime Minister Scott Morrison backing the idea in 2018.
“Senior ministers made reference to: ‘if that was a solution to agricultural labour shortages, it's something they would actively look at it’," Mr Pezzullo said.
He recalled a senior minister pledging to consider the visa but said the government chose not to pursue it.
“We will work to establish an agriculture visa — that is the long-term solution, even the medium-term solution,” Mr Morrison said in 2018.
The PM later backed away from the commitment after increasing intakes across a handful of seasonal labour schemes.
The workforce strategy released two weeks ago recommended against a specific visa.
Senator Cash said the government introduced a number of temporary visa measures during the coronavirus pandemic designed to help with labour shortages in agriculture.
During the 2019 election campaign, Nationals leader Michael McCormack and Federal Agriculture Minister David Littleproud expressed support for the proposal.
“I am a believer in an ag visa and I know the PM wants to move towards it,” Mr Littleproud said.
Mr McCormack declared "we'll get it done" after working out the most viable way to achieve a dedicated visa.
“The ag visa is important,” he said.