"Turnbull is the problem, the Prime Minister is the problem", he told 2GB.
Mr Howard later told the newspaper that "there seems to be an outbreak of madness at present".
Just this week, Nationals backbencher Andrew Broad accused Mr Turnbull of a failure of leadership, in another sign of growing tensions inside the federal Coalition.
Mr Barilaro's comments come just 24 hours before the polls open in the New England by-election being contested by former Deputy Prime Minister Barnaby Joyce.
Turnbull volleyed back on Melbourne radio station 3AW, saying that Barilaro had never raised these issues with him personally.
In an explosive interview this morning, John Barilaro demanded Malcolm Turnbull step aside before Christmas.
'You've got a party in disarray, a coalition government in disarray and a community not unified, and that is all at the feet of the prime minister of Australia, ' Mr Barilaro said.
Mr Howard has told the Weekend Australian that he continues to strongly support Mr Turnbull and that the Liberal Party needs to help make his leadership successful.
Barilaro was particularly incensed with Turnbull's assertion that the Queensland state election results had nothing to do with the federal government's performance, which everyone knows is not really the case in any way you'd like to name.
Mr Barilaro said "desperation" has led him to call on the PM to stand down with the decision yesterday to announce a Royal Commission into the banks the final straw.
When asked whether his time was running out Mr Turnbull responded "absolutely not".
"If that was a serious view he held you would think that he would speak to me directly".
'If I had a view about a state leader of that kind, I would express it - if I expressed it at all - privately and face-to-face, I wouldn't be bagging them in the media like that'.
Howard has seemingly had enough of the political backstabbing and has thrown his full support behind Turnbull.
Ms Berejiklian said she looked forward to working with the Turnbull government to deliver better quality lives for the people of NSW.
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