US President Donald Trump will unveil the latest round of tariffs on Thursday morning, Australian time, and his so-called "Liberation Day" is threatening to up-end the federal election campaign.
Foreign Minister Penny Wong has all but conceded Australia is unlikely to avoid being hit, although officials are still trying to get a carve-out from the imposts on exports to the US.
"We'll keep working hard for the best outcome, but I think all of us are realistic," she told ABC Radio on Wednesday.
"President Trump has made it very clear that imposing tariffs is a central plank of his economic agenda."
Both Prime Minister Anthony Albanese and Opposition Leader Peter Dutton - who are beginning the fifth day of their campaigns in Melbourne - have said there will be no compromises on biosecurity or pharmaceuticals for the US in exchange for a tariff deal.
Mr Dutton said he would stand up to the US president, if he becomes prime minister at the May 3 election.
"If I needed to have a fight with Donald Trump or any other world leader to advance our nation's interests, I do it in a heartbeat, and I'll put the Americans on notice," the coalition leader told Sky News.
"I'm not going to allow the president of the United States or the prime minister of the United Kingdom or anyone else to walk over me or to walk over our country.
"At the moment they see a prime minister who is weak and flapping in the breeze."
Senator Wong said Mr Dutton was yet to say how he would support the nation.
"Is he going to back Australia, or is he going to back the imposition of tariffs? Because ultimately, this comes down to do you back Australia," she said.
A recent report by the US Trade Representative took issue with trade barriers imposed by Australia on US goods such as beef, pork, chicken, apples and pears.
The document also pointed to issues over Australia's treatment of pharmaceutical patents and its news bargaining code, which is aimed at making technology platforms pay local media organisations for content.
Mr Albanese said all of those elements were not up for debate.
"I want to see a constructive outcome, but what I won't do is undermine our national interest," he said on Tuesday.
Nationals Leader David Littleproud said if Mr Trump imposed tariffs on agricultural imports, it would result in economic self-harm for the US.
"If he looks at Australian beef and he wants to slap it on Australian beef, he, in fact, will be slapping it on his favourite food - a Big Mac - because most of the meat that goes into a Big Mac is lean beef and it comes from Australia," Mr Littleproud told ABC TV on Wednesday.
"This will be a tax on Americans.Â
"So while it might sound good, what President Trump is doing, there are consequences."
Meanwhile, Mr Albanese and Mr Dutton will on Wednesday seek to shore up voter support in Melbourne, where many marginal seats could decide the election.
The prime minister will make a pitch to workers by highlighting the government's push for an above-inflation pay rise for low-paid workers in its next submission to the industrial umpire.
Mr Dutton has used his time in Melbourne to talk up a crackdown on crime.
The Greens are pushing a policy to direct one per cent of the federal budget toward protecting the natural environment to prevent further extinctions.
The minority party says this will be a key bargaining chip if the election ends in a hung parliament.
