Australian Greens senator Sarah Hanson-Young has been reduced to tears during an upper house debate on contentious legislation that legalises the offshore processing of asylum seekers.
The Senate has begun debating a bill that would allow the government to implement its people-swap deal with Malaysia and permit the reopening of a detention centre on Nauru.
The bill, which cleared the lower house on Wednesday night, faces defeat in the Senate where the combined vote of the coalition and the Greens outnumbers Labor.
Government leader in the Senate Chris Evans said there was an expectation from the Australian public that senators resolve the issue "one way or the other today".
The debate is expected to last several hours, replacing other business including question time.
Greens senator Sarah Hanson-Young cried as she told the story of a 15-year-old Afghan orphan called Hussein, whose sister sacrificed everything she owned so he could have a better life in Australia.
Hussein was one of 500 people locked up on Christmas Island waiting to find out if he was going to be sent back to Malaysia before the High Court quashed the arrangement last year.
Now he is living with a family in Australia, learning English at school and will make "a fine Australian".
"These are the lives of the people we are playing with," Senator Hanson-Young said.
"When people arrive on your doorstep you have an obligation to help them."
Senator Evans urged the upper house to find some clarity and not be swayed by political and emotional considerations.
"We have one opportunity to do something today," he said.
"It's our one chance to get this right." But the former immigration minister admitted the Oakeshott bill challenged his personal moral stance.
"I was the one who closed Nauru, I was the one who got rid of temporary protection visas," Senator Evans said.
He said reopening Nauru had caused much angst among some Labor MPs but a compromise needed to be reached.
Senator Evans said the Malaysia deal would make a dent in the people smuggler's business model.
"It will work ... you have to provide a deterrence."
Senate opposition leader Eric Abetz said Australia had to decide whether it wanted to allow some asylum seekers to buy their way into the country, assisted by criminals.
He dismissed as "no solution" the Oakeshott bill because the government had said it would not transfer women and children to Malaysia.
People smugglers would simply load up their boats with women and children to get around the law.
"Compromise per se has never been a substitute for good policy," Senator Abetz said, adding the ability to turn back boats if it was safe should be in the government's armory.
The coalition wants offshore processing limited to the 148 countries that are signatories to the UN refugee convention.
That would rule out Malaysia, but allow Nauru and Papua New Guinea.
Australian Prime Minister Julia Gillard earlier appealed to senators to look into their consciences over the laws.
''There's a very stark choice for senators today,'' she said this morning.
''Either they vote for this bill and we will leave this parliament with laws so we can process people offshore or they continue to play politics and we end this parliament with nothing effective done.''
Home Affairs Minister Jason Clare warned there was a ''real risk'' more people would die if the Senate failed to pass the bill.
Reports of a distress call this morning from a boat carrying asylum seekers en route to Australia were a false alarm.
Martime officials in Australia say the boat was apparently a fishing vessel.
The Australian Maritime Safety Authority said the vessel in trouble 20 nautical miles off Indonesia did not appear to be carrying asylum seekers.
Authorities are edgy after a vessel carrying about 130 people sank north of Christmas Island with four lives lost yesterday, sparking intense scenes in Parliament.
And last week dozens of people were killed when another boat capzised in the area. More than a hundred other people were pulled alive from the sea.
Australia is a common destination for boats carrying asylum seekers from Afghanistan, Iraq, Sri Lanka and other poor or war-torn countries.
In December 2010, an estimated 48 people died when an asylum seeker boat broke up against Christmas Island's rocky coast.
Last December, about 200 asylum seekers were feared drowned after their overcrowded ship bound for Australia sank off Java.
Other boats are suspected to have sunk unnoticed with the loss of all lives.
- Fairfax and AAP