Barnaby Joyce says Malcolm Turnbull should not represent Australia at an oceans conference in Bali because he didn't campaign in the Wentworth by-election.
Prime Minister Scott Morrison says he was unable to attend the Our Ocean Our Legacy conference so he asked Mr Turnbull to instead go to the October 29-30 event.
"It was the subject of our discussions when I met with the Indonesian president, President (Joko) Widodo," Mr Morrison told parliament on Tuesday.
"I did request the former prime minister to represent us at that conference, and he'll be there representing the policies of our government."
But former deputy prime minister Barnaby Joyce says the move was "pretty wild", especially given Mr Turnbull refused to campaign for Liberal candidate in Wentworth, Dave Sharma, and now the coalition has lost its majority..
"Doesn't stack up for me either. If I was in the cabinet, I'm not, I'd be scratching my head desperately," he told 2GB radio.
"Now I'm on the backbench I can tell you the truth: it is a problem and there should have been a bit more thought put into this, I don't think it's the right move."
Mr Turnbull sent a tweet supporting Mr Sharma and also sent private messages to him, but did not actively campaign while he was overseas.
"I think he's angry about losing his job, I don't know, one can only presume some sulking. It's something you've got to get over with," Mr Joyce said.
"I suggest that probably gives us a very good reason not to send him to Bali."
Mr Morrison said President Widodo appreciated Mr Turnbull's decision to go.
Mr Turnbull famously had a good relationship with the Indonesian president, and Mr Morrison said sending the former prime minister was a signal of how seriously Australia is taking the conference.
Independent Kerryn Phelps is ahead in the Wentworth count, but the final result has not yet been declared.
Australian Associated Press