Labor continues to push Malcolm Turnbull over marriage equality, saying it's the prime minister's problem if he loses his job over the fraught issue dividing the Coalition.
Asked about whether a free vote on the issue would cost Turnbull his job, Plibersek said “Sure, but that is his problem”.
"It's not our job to save his job," she said. "It's our job to legislate, that's our day job, that's what we're paid to do."
"If only [Malcolm Turnbull] had some real power like being prime minister or something, wouldn't that be fantastic?"
Last week, Nationals MPs issued thinly-veiled threats to prime minister Malcolm Turnbull on the havoc they might wreak if he steps away from the government's plebiscite policy.
Nationals MP Andrew Broad threatened to bring down the government over the issue, saying his position as a member of the government was conditional on it.
Nationals whip George Christensen said the plebiscite was in the top-secret agreement between the Nationals and the Liberals and that any steps away from that would be a very serious matter.
Plibersek said the Coalition should not roll Turnbull on the issue, and criticised conservatives for wanting to "roll a prime minister because he wants to do what is in his heart".
“They should back their prime minister on an issue of principle for him,” she said.
Plibersek also said Labor would take “full political and moral responsibility” if marriage equality is now not legislated in this term of parliament.
She stressed Labor's decision was made in consultation with the LGBTI community, who largely expressed a desire to wait rather than have a plebiscite on the matter.