About 100 asylum seekers will be hunting for jobs and homes immediately after the federal government launched a surprise move to cut them off welfare.
The immigration department has told asylum seekers in Australia they'll lose a $200-a-fortnight payment from Monday and have three weeks to move out of government-supported accommodation after being moved onto a "final departure Bridging E Visa".
Up to now they have been prevented from working, refugee advocates say.
"And now, completely out of the blue, with no notice whatsoever, they've been told tomorrow, you have no income we're taking all of your income away and in three weeks time we're taking your homes away," Human Rights Law Centre executive director Hugh de Kretser told reporters in Melbourne.
His centre and the Asylum Seeker Resource Centre say about 100 people will be immediately affected by the Turnbull government's crackdown, but estimates the number could be as high as 400.
Those affected include people who have come to Australia from offshore detention centres for medical treatment.
Human Services Minister Alan Tudge says did not think it was unreasonable to withdraw taxpayer support if they refused to return to Manus Island or Nauru.
Greens leader Richard Di Natale is taking advice on whether the move could be stopped in the Senate when parliament returns next week.