One Nation Leader Pauline Hanson has raised millions of dollars for an anti-Labor advertising campaign using the "fire the liar" line.
Matt Canavan said he would work with anyone to get rid of the government and Treasurer Jim Chalmers "should go", following contentious tax changes in the budget.
"Everyone wants to fire the liar," the Nationals leader told Seven's Sunrise program on Monday.
A poll released on Monday showed One Nation could win between 54 and 63 seats if an election were held now.
Labor would retain government but could be in minority with between 65 and 74 seats, the DemosAU survey published by Capital Brief shows.
The coalition would hold between four and 11 seats, while the Greens and independents would each have fewer than 10.
It is the latest in a series of polls showing mounting support for One Nation.
Liberal MP Garth Hamilton urged his colleagues to be "cool, calm and confident" in presenting voters with a strong alternative to One Nation.
"We can't dismiss the areas of concern that people are speaking to," Mr Hamilton told AAP.
"We also can't shy away from the differences between us and One Nation."
The debate comes as the government attempts to strike a deal on contentious tax and disability reforms aimed at getting the nation's finances on a more even keel.
Labor is offering to extend an inquiry into an overhaul of the National Disability Insurance Scheme in exchange for the Greens supporting its move to wind back tax breaks for investors.
The changes to capital gains tax have sparked a political firestorm, but Dr Chalmers said opponents of the reforms were mounting a disingenuous scare campaign.
"There will still be a discount on capital gains, but it will be fair reflection of inflation rather than the Howard approach, which has distorted investment in our economy for a quarter of a century now," Dr Chalmers told parliament.
Opposition Leader Angus Taylor said the tax changes should be scrapped and accused Labor of shifting to the "crazy left" to strike an agreement with the minor party.
"That dirty deal between Labor and the Greens is, I think, something every Australian should be deeply concerned about," he told reporters in Canberra on Monday.
"We don't need a carve-out, we need an axe. This budget has been a flop and the flop should be dropped."
Mr Taylor said he wanted more scrutiny of the NDIS reforms but indicated he would work with the government to make the scheme more financially sustainable.
The NDIS changes have angered advocates who have warned some disabled Australians could die if the government's cuts are implemented.
The Greens want the bill scrapped, but as a last resort, will attempt to delay its passage by extending a parliamentary inquiry into the proposal.
"Every day that bill doesn't pass is a day that the community is saved from these vicious, nasty, mean cuts," Greens senator David Shoebridge said.
The Greens attempted to have the NDIS overhaul thrown out of parliament on Monday.
The coalition initially supported the push but opposed it when the motion came to a final vote.
