Malcolm Turnbull has branded Communications Minister Stephen Conroy a grub as a debate about the national broadband network turned into a slanging match.
The pair were debating their respective NBN policies on Monday, each defending the merits of their plans for faster internet speeds, when the argument degenerated into personal insults.
The row escalated after Mr Turnbull suggested Senator Conroy had been incompetent during negotiations with Telstra over access to its copper network for the NBN.
Mr Conroy responded by questioning advice that Mr Turnbull gave in the late 1990s during his time as a corporate lawyer.
A clearly angry Mr Turnbull retorted: "You are so desperate that all you can do is smear and abuse.
"That's the best you can do. You poor fellow.
"You're such a mess, you're such a grub, Stephen. You're such a sad figure."
In the 45-minute debate, hosted online by tech website ZDnet, Mr Turnbull failed to rule out funding cuts for the ABC and SBS under a coalition government.
"I can't give an undertaking in a budgetary context that is being left in a mess by Labor with this massive deficit," he said in response to a question about public broadcast funding from Senator Conroy.
"Who's to say - there may be cuts right across the board.
"But there is certainly not any plan, any policy to target the ABC or SBS for any funding cuts of the kind that are being canvassed by Labor.
"But if there is a broader austerity of some kind, across the board, then all departments may have to bear some of the pain."
Senator Conroy said Labor had boosted funding for the two broadcasters and would offer more in next week's federal budget.
"We have increased the funding significantly for SBS, the biggest increase for the ABC, and we've got more coming in the budget," he said.
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