Legal experts and refugee advocates are appalled by the Coalition’s proposed life ban on asylum seekers who arrive by boat.

Prime Minister Malcolm Turnbull announced on Sunday his government will attempt to amend the Migration Act to prevent “irregular maritime arrivals” from ever applying for an Australian visa.

“The door to Australia is closed to those who seek to come here by boat with a people smuggler. It is closed,” Mr Turnbull told reporters.

Immigration Minister Peter Dutton says the bill will stamp out ‘false hope’. Photo: AAP

“As of today, asylum seekers who come here by boat without a visa will never be settled in Australia.”

If enacted, the law would be an effective life ban on any person processed in an offshore refugee centre from entering Australia, and would be backdated to July 19, 2013.

It would apply even if boat arrivals were found to be genuine refugees, and would extend to all types of visas, including for the purposes of tourism and business. But children would be exempt.

Barrister Greg Barnes, a spokesman for the Australian Lawyers Alliance, said the proposed law is “extraordinary”, and warned it could lose a High Court challenge because it is “completely antithetical” to Australia’s obligations under the UN Refugee Convention.

“The idea that you can ban people from even making a claim under the Convention simply on the mode of transport is, I think, something the High Court would have some real difficulty with,” Mr Barnes told The New Daily.

“The High Court may take a dim view of this particular provision because it’s so extreme.”

If enacted, the law would be a world first, Mr Barnes said.

“I’m not aware of any other country in the world that discriminates against people or refuses to allow them to make a claim for asylum simply on the basis of their mode of transport,” he said.

“It’s no more than a political stunt. The government likes to proudly proclaim on the one hand that it’s stopped the boats, and yet on the other hand it feels the need to pass a law of such an extreme and unprecedented nature to prevent boats coming to Australia. You can’t have it both ways.”

During the press conference, Mr Turnbull said no refugee boat had reached Australia in more than 800 days.

Immigration Minister Peter Dutton added to the announcement by saying the intent of the law was to stamp out “false hope”.

The Labor Party has not yet clarified its position on the proposed law. During the press conference, Mr Turnbull and Mr Dutton pressured the opposition to support it, citing the immigration policies of former PM Kevin Rudd.

The federal government wants to prevent any asylum seekers who try to come to Australia by boat, even those found to be refugees, from ever entering the country. Photo: AAP

While deputy leader Tanya Plibersek wouldn’t confirm if the opposition will vote against the measure, she criticised it is a “distraction” from Mr Dutton’s “hopeless mismanagement of his portfolio”.

Refugee Council of Australia CEO Tim O’Connor said the proposal was “extremely concerning”, not least because it leaves in limbo an estimated 3000 refugees living in Australia who arrived by boat since 2013.

“It seems extraordinary that the government would mete out such severe punishment,” Mr O’Connor told The New Daily.

“It is typical of the really ad hoc nature which consecutive governments have approached this area in recent years. We’ve seen this real discrimination targeted at people because of their mode of arrival.”

The Greens have implored Labor to oppose the amendment, while One Nation leader Pauline Hanson praised the government for yet again “taking its cues” from her party.

Good to see that it looks like the Government is now taking its cues from One Nation. Just like last time. #auspol #PHON #Nauru #Manus https://t.co/c0GQew7vR8

— Pauline Hanson 🇦🇺 (@PaulineHansonOz) October 30, 2016