Joyce says NSW Nats leader 'insulting'

Barnaby Joyce has labelled John Barilaro "insulting" and "unhelpful" after the NSW Nationals leader called on the prime minister to quit by Christmas.

Mr Barilaro - the NSW deputy premier - on Friday said he'd lost all faith in Malcolm Turnbull, who he described as "out of touch".

That intervention in Canberra politics drew a stinging rebuke from Mr Joyce, who remains the federal Nationals leader despite facing a by-election on Saturday to regain his seat of New England.

"I was very disappointed with the comments by the (NSW) deputy premier this morning," Mr Joyce told reporters in Tamworth on Friday afternoon, adding the comments were "very unhelpful" and didn't profit anybody.

"I find them insulting ... I can't fathom how people could think a comment like that is of anything but harm.

"You're criticising the captain of your own team ... why would you do that?"

Mr Joyce insisted the Liberal Party was a "business partner" of the Nationals. Mr Turnbull was his personal "mate".

"If what you want to do is tear down the coalition then what you're actually doing is asking that (Opposition Leader) Bill Shorten become prime minister of Australia," Mr Joyce concluded.