The Turnbull government has been accused of sinking to “a new low” after leaked documents revealed it plans to kick up to 100 Australia-based asylum seekers off income support on Monday.

But the government said the plan was consistent with the principle that asylum seekers who come to the country by boat will not be settled in Australia – a policy both major parties support.

Human Services Minister Alan Tudge confirmed a group of asylum seekers initially brought to Australia for medical treatment would be transferred onto the new ‘final departure Bridging E Visa’.

The group will lose a fortnightly welfare payment of about $200 and be removed from government-supported accommodation, sparking fears they could end up on the streets.

While they will be granted working rights, refugee advocates expressed concern that many will struggle to find immediate housing and employment.

Opposition Leader Bill Shorten said the policy was a result of “weak prime minister trying to look tough” while immigration spokesman Shayne Neumann claimed the government had sunk to a “new low”.

“Kicking people onto the streets with no support is needlessly cruel and really, really dumb,” Mr Shorten said.

“It won’t fix anything. It’s just hurting vulnerable and sick people for the sake of it.”

The asylum seekers are part of a group of about 400 who were transferred from Nauru or Manus Island to Australia, and which the government now wants to leave the country. Refugees advocates have fought in the courts to allow them to stay.

Mr Tudge said the asylum seekers had received treatment and were now required to return back to Nauru or Manus Island or their home country.

“That is what they need to do, and I do not think it is unreasonable for us to therefore withdraw taxpayer support if they refuse to return back to those countries,” he told Sky News.

Immigration Minister Peter Dutton is responsible for Australia’s asylum seeker policy. Photo: AAP

The group will still receive Medicare support where necessary, government frontbencher Dan Tehan said.

The new conditions were revealed in a leaked Immigration Department letter, published by Fairfax Media, which tells asylum seekers: “You will be expected to support yourself in the community until departing Australia.”

“From Monday 28 August you will need to find money each week for your own accommodation costs. From this date, you will also be responsible for all your other living costs like food, clothing and transport.”

They will also be required to sign a Code of Behaviour, the letter states.

Greens leader Richard Di Natale, who labelled the move “unspeakable cruelty”, said his party would attempt to block the new visa in the Senate next week.

Human Rights Law Centre executive director Hugh de Krester said it “defies belief that any decent government could act in this way”.

“They’ve been prevented from working,” he said. “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’.”

Trump administration officials are believed to be in the process of vetting asylum seekers on Manus Island and Nauru under the refugee swap deal struck with former president Barack Obama.

The deal says that 1250 refugees will be settled in the US, but Donald Trump’s decision to impose “extreme vetting” on new entrants to the country has cast doubt on the arrangement.

The Manus Island regional processing centre is slated to close on October 31.