Opposition Leader Bill Shorten has accused Prime Minister Tony Abbott of washing his hands of the asylum seekers.
Mr Abbott has described a report that a dozen mothers have attempted suicide on Christmas Island so their children might remain in Australia as harrowing.
But he says his Government will not be held to what he calls "moral blackmail" when it comes to asylum-seeker policy.
Mr Shorten says Mr Abbott's statement shows he is abandoning responsibility for the safety of asylum seekers in his care.
"I cannot accept from this Government that it can simply wash its hands of the safety of people in our care.
"I get that Mr Abbott doesn't want these people to be in the care of the Australian government. But we are signatory to international conventions, they are in the care of Australia, and the Australian government. It is not enough to wash their hands, (for) the Government to wash its hands, of the safety of people in the care of the Australian government."
Greens senator Sarah Hanson Young accused the Prime Minister of being "morally bankrupt".
"It's a little hard to succumb to moral blackmail when you already morally bankrupt - and this government's policy is forcing such already desperate and vulnerable people to a point of self-destruction."
Meanwhile, former foreign minister Bob Carr has rejected claims that asylum seekers are mistreated when they return to Sri Lanka.
"I saw no example when I was foreign minister of this dire picture emerging - that is of people being held in detention on being returned - we couldn't find a single case of this," he told the ABC.
