The Turnbull government plans to introduce legislation to ban asylum seekers who arrive by boat from ever being allowed into Australia.
The ban will apply to any adult who has been sent to detention centres on Nauru or Manus Island since 19 July 2013.
It means adults who have previously tried to enter Australia by boat since July 2013, but who have chosen to return home, will never be allowed to get a visa to Australia – even as a tourist, or a spouse.
The government plans to backdate its ban to 19 July 2013, because that is when the former prime minister Kevin Rudd said: “As of today, asylum seekers who come here by boat without a visa will never be settled in Australia.”
The ban will not apply to children.
Malcolm Turnbull announced the plan on Sunday during a joint press conference with the immigration minister, Peter Dutton.
He said the law change was necessary to support key government border protection policies, including temporary protection visas, regional processing and boat turnbacks.
He said it would send the “strongest possible signal” to those who are trying to persuade asylum seekers currently on Nauru and Manus Island that Australia’s government would eventually change its policy and allow them to settle in Australia.
He said this was a “battle of will” against criminal people smugglers and Australians “should not underestimate the scale of the threat”.
“These people smugglers are the worst criminals imaginable,” Turnbull said. “They have a multibillion-dollar business. It is a battle of will. We have to be very determined to say no to their criminal plans.”
The government plans to amend the 1958 Migration Act to achieve its goal when parliament sits next week.
Turnbull said he expected Labor’s support for the legislation, given it was “entirely consistent with the party’s stated public position” from 19 July 2013.
“Mr Shorten now has the opportunity to express clear, unequivocal support for this very strong statement of long-standing Coalition, and so far as we understand opposition, policy,” he said.
“They must know that the door to Australia is closed to those who seek to come here by boat with a people smuggler: it is closed.
“We accept thousands of refugees and we do so willingly. But we will not tolerate any repeat of the people smuggling ventures which resulted in over 1,200 deaths at sea under the Labor party, and 50,000 unauthorised arrivals.”
Dutton said some asylum seeker advocates were still telling people on Nauru and Manus Island that they would be coming to Australia at some stage.
“And those people are living in false hope and it cannot continue,” he said.
“So today, through this legislation, we send a very clear message to all the parties concerned that Australia will never be an option for people to seek to come here illegally by boat.”
He said the measure would also prevent refugees from Manus Island and Nauru from marrying Australians in a bid to come to Australia on a spouse visa.
“We are not going to allow arrangements that would subvert the program and the success that we’ve had within this process,” he said.
The deputy opposition leader, Tanya Plibersek, said it was too early to say if Labor would support the bill.
“It’s a distraction from Peter Dutton’s hopeless mismanagement of his portfolio,” she said. “It is extraordinary that, three years on, the government has not found third countries to resettle those people who are in limbo on Manus Island and Nauru.”
Turnbull dismissed the suggestion that the measure would be unfair to those deemed to be refugees who had tried to get to Australia by boat, given it would prevent them from getting any type of visa in the future.
“It’s a very clear, unequivocal message,” he said.
David Manne, from the Refugee and Immigration Legal Centre, said the government’s proposed ban appeared to be “completely unnecessary”.
“Why are these measures seen as necessary when the government for some time has said they have got things under control?” he said on ABC television.
Manne questioned whether the flexibility the government has to exercise humanitarian discretion would be lost in this change.
“It would not only be unnecessary this policy, but also extremely potentially counterproductive because there are always going to be people ... who simply cannot be resettled anywhere or sent back,” he said.
The Greens criticised the announcement, saying the Turnbull government had “sunk to a new low” in its “latest attempt to punish innocent people seeking asylum”.
“The proposed new laws are an escalation of the cynical race to the bottom, which sees our fellow human beings again used as a tool to seek domestic political advantage,” the Greens immigration spokesman, senator Nick McKim, said.
“This is about absorbing nothing more than One Nation votes. As Amnesty International recently made plain, the mistreatment of people for a political purpose is torture.
“It runs contrary to international law and our obligations under the refugee convention. The government should have been aware of this, but of course they have just run the solicitor general out of office.”
The One Nation leader, Pauline Hanson, welcomed the government’s proposal, tweeting: “Good to see that it looks like the government is now taking its cues from One Nation. Just like last time.”
Dutton said under the government’s proposal, if someone was under 18 years of age when they were transferred to a regional processing country they would be exempt from the legislation.
