DEPUTY Prime Minister Michael McCormack has taken an extraordinary swipe at Barnaby Joyce, after the backbencher argued the Nationals were not "married" to the Liberal Party.
Mr McCormack said he understood what it took to have a successful marriage.
"I understand when you have a marriage that it's a two-way relationship," he said in Queensland on Monday.
"You don't always get what you want but you have to work together to build better outcomes for your family."
His comments were ostensibly aimed at managing tensions between the coalition partners over energy policy.
But they will carry a significant sting for Mr Joyce who lost the Nationals leadership and whose marriage broke down last year after having an affair with a staff member.
Mr Joyce said in a statement: "I would hope nobody in politics revels in the personal issues of others and I hope that this is not the case this time."
He later added on Sky News that he had been hurt "a bit" by Mr McCormack's comment, but would take it as a "faux pas".
He rejected the comparison of the Liberal-National coalition to a marriage, saying it was more like a "business relationship", in which both parties carved out deals for their constituencies.
Earlier on Monday, Mr Joyce sensationally claimed he remained "the elected deputy prime minister of Australia" and would feel no guilt in returning to lead the National Party if Mr McCormack was rolled.
"I am not going to call a spill, I am not looking for numbers," Mr Joyce told ABC Radio National.
"If there was a spill, the position is vacant, I am the elected deputy prime minister of Australia, so I'd have no guilt at all standing - but I don't see that happening."
He made the explosive remarks after demanding the Morrison government bankroll a new coal-fired power station before the next election.
Investment in coal-fired power would be electoral poison in Liberal-held seats in southern states, where voters are demanding stronger action on climate change.
But Mr Joyce angrily rejected suggestions he was hurting the coalition's chances of re-election.
Prime Minister Scott Morrison rebuked Mr Joyce, insisting there will be "no change" to his leadership team.
"We have a fantastic leader of the National Party and deputy prime minister in Michael McCormack" he said from Sydney.
Nationals MP Andrew Gee, the deputy prime minister's right-hand man, insists his position is not under threat.
"If it's one thing the Australian people (have) made clear in recent times it's that they're not happy with leadership shenanigans," he told the ABC.
Queensland Nationals MP Keith Pitt, who is among those pushing for new investment in coal, is not impressed the issue has morphed into a proxy battle for leadership.
"The leadership of the party is a gift of the party room," he told Sky News.
"Michael McCormack is the leader, there will be no change."
Senior Labor frontbencher Chris Bowen was bemused by the leadership rumblings, saying on Twitter: "It's a Venezuelan style stand-off between two blokes who think they are the deputy prime minister. I reckon we just give Tanya Plibersek the job."
Australian Associated Press