Australia is a big island with a small population that is ageing. With a low birth rate, migrants are the best way to grow the economy. A plan to forever ban refugees who arrive by boat from settling or even visiting is therefore strange. But coming amid a growing backlash in Europe against millions of asylum-seekers from the Middle East and Africa, the idea also sends a worrying message to other governments.

The nation’s existing policy of indefinite offshore detention for asylum-seekers arriving by sea has long been the target of international condemnation. Those who are intercepted are sent to detention camps on Papua New Guinea’s Manus Island and the nation of Nauru, where the United Nations and rights groups have criticised conditions. Prime Minister Malcolm Turnbull’s proposal would apply to adults among the 1,200 being held in the camps. If the support of independent and opposition lawmakers is won, it would split families and prevent reunions with relatives already in Australia, while dooming the future prospects of refugees and fuelling the campaigns of anti-migrant groups elsewhere. Yet Australia is a nation built by immigrants, the result of a decades-old open-door policy. A quarter of Australians were born overseas and 43 per cent have at least one parent who was foreign-born. Some of the nation’s most celebrated people were refugees, among them South Australian state Governor Hieu Van Le and the 1998 Young Australian of the Year, technology entrepreneur Tan Le, who both arrived by boat. But asylum-seekers make up only a small part of the annual migrant intake, amounting last year to 15,790 applications among the about 185,000 taken in, and of them, only a few hundred came by sea. Far more visitors and students overstay their visas.