The Greens have disrupted Senate business to decry the federal government's ability to send Australia to war alongside the US without parliamentary debate.
Greens leader Richard Di Natale moved to suspend business on Monday morning insisting the prime minister could not even stand up to "homophobic bullies" in his own party let alone US President Donald Trump.
"How deeply ironic that we have a government refusing to legislate for marriage equality without resorting to a needless postal poll yet it can decide to send men and women to war ... without so much as a parliamentary debate," he told senators.
Malcolm Turnbull last week confirmed Australia would come to the aid of the US if it was attacked by North Korea, insisting both nations are joined at the hip on defence.
What form that aid took would depend on the circumstances and consultation between the two nations, he said.
Senator Di Natale wanted the Senate to debate a private bill that would require parliamentary approval before the government commits Australia to war.
Australia needed to rip up the ANZUS agreement and renegotiate its relationship with the US.
"It is a relationship that endangers indeed humanity on earth," he said.
Attorney-General George Brandis said Senator Di Natale's "intemperate" speech was exactly why decisions of such gravity should be made by government, informed by military chiefs.
It was "fanciful" to suggest such a grave decision could be made in a partisan way.
"No government would make a decision of such a kind lightly," he said.
The stunt was shut down with Labor opposing the move and voting with the government.
