Barnaby Joyce has accused Malcolm Turnbull of trying to bring down the government after the former prime minister lobbied his successor to refer Peter Dutton to the High Court.
"It seems like he has an active campaign to try and remove us as the government. Boy, that is bitterly disappointing," he told reporters in Canberra on Thursday.
Mr Joyce said it would be fair to characterise Mr Turnbull's intervention as "wrecking and sniping".
He argued coalition MPs gave the former prime minister loyalty and expected it in return, warning Mr Turnbull risked impugning his legacy.
"It's not so much how you rode the horse, it's how you get off it that counts," Mr Joyce later told Sky News.
"Some people get off sweetly out of the saddle and walk to the rails. Some people just want to keep one foot in the stirrup and get dragged around for a bit, and it doesn't look good."
Mr Dutton is under a constitutional cloud over his personal financial stake in publicly-funded childcare centres, which his critics claim presents a conflict of interest.
Asked whether the Home Affairs minister should be referred to the High Court, Mr Joyce said Mr Dutton was an honourable person.
"I'm not going to start being someone else's judge and jury."
Mr Joyce served as deputy prime minister to Mr Turnbull before being forced to resign, with the pair falling out over the former Nationals leader's affair with a staffer.
Mr Joyce referred himself to the High Court earlier this year after discovering he was a dual citizen, putting him in breach of the constitution.
Australian Associated Press