An alleged deal on one party giving the other supply and confidence is in the works, according to Mr Joyce, but that was strongly rejected by coalition spokespeople on Wednesday.
"We're having conversations, and everybody knows," the former deputy prime minister told News24.
"There is no prospect in current polling that the coalition can form government, nor can One Nation."
Mr Joyce refused to reveal whom he had spoken to as Liberal party members lined up to dismiss his claims.
"I think they're a figment of Barnaby's imagination," opposition frontbencher Tim Wilson told News24, responding to reports of the senior-level talks.
Mr Wilson theorised his former coalition comrade's comments came from being sore about defecting from the Nationals in December 2025.
"I understand Barnaby has regrets about jumping over to a new political party where he doesn't pull the strings and is now just operated by others," he said.
In response, Mr Joyce accused Mr Wilson, who is opposition treasury spokesman, of being unable to count to 76, the number of lower house seats needed to form government.
Deputy Liberal leader Jane Hume also said she, Liberal leader Angus Taylor and Nationals leader Matt Canavan were unaware of discussions with One Nation.
"I'm pretty sure that that this is Barnaby clutching at straws," she told News24 on Wednesday.
"Perhaps he's got some sort of post-purchase dissonance ... I have absolutely no idea exactly what it is that Barnaby is discussing, or who he's discussing it with."
But One Nation is steaming ahead of the coalition on primary vote at 30 per cent, compared to their centre-right rivals' 19, according to the latest Newspoll figures released on Sunday.
The Liberal party has splintered about whether to cosy up to the anti-immigration party, or distance itself.
"We won't be formalising a coalition with One Nation, but what I will be doing is working with anyone to get rid of this Labor government," Liberal MP Simon Kennedy told News24 in response to Mr Joyce's claims on Wednesday.
"I'll work with anyone - literally anybody ... if that's the crossbench, if that's the independents."
Cooperation between the two parties also has the strong support of freshly minted South Australian Liberal party president, Senator Alex Antic, who on Monday became the most senior coalition member to back the idea.
Senator Antic has close ties to One Nation leader Pauline Hanson as well as with Cory Bernardi, who heads up the party's SA division, but has stressed his views on collaboration are his own and not the coalition's.
