Australia’s prime minister is campaigning to block a bill which would allow refugees in offshore camps to visit the country for medical treatment.

Under the country’s immigration policy, those who arrive by boat have been sent to camps in Papua New Guinea and Nauru and are not allowed to set foot in Australia even if found to be refugees.

Those opposing the policy have introduced a bill to amend the Migration Act to allow the temporary transfer of these people to Australia for medical assessment.

The Australian Medical Association has backed the bill – but the government fears it could open a loophole that asylum seekers could exploit.

“We cannot have Australia’s borders determined by panels of medical professionals,” prime minister Scott Morrison told a news conference on Saturday.

Barcelona Refugee Squat - 'Casa Africa' Show all 36 1 /36 Barcelona Refugee Squat - 'Casa Africa' Barcelona Refugee Squat - 'Casa Africa' A Casa Africa occupant prepares to serve food to supporters and fellow refugees Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A member of the local community outside Casa Africa Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Adam (left), aged 18 from Senegal, left behind a sister, two brothers and his mother because of ´political problems´ in his country. He said: "My dream is to help my family. In Senegal is difficult because of the war and fighting, it´s dangerous." Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Graffiti in the squat where some asylum seekers have been staying reads: "We don't go slow, we go far" Anu Shukla Barcelona Refugee Squat - 'Casa Africa' People share food in the street following news that the eviction of asylum seekers from the squatted building is postponed Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Various members from Barcelona's different solidarity networks pose for a photograph Anu Shukla Barcelona Refugee Squat - 'Casa Africa' La Teixidora has been occupied by various people over the last couple of decades and has been frequented by the city party crowd for raves over many years Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Locals queue up for a celebratory lunch after receiving news the squat eviction has been postponed Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A member from one of the solidarity networks focusing on administrative support for refugees Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Mahe, 24, an artist from Columbia has been supporting asylum seekers in the city over the last year or so Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Asylum seekers who have taken refuge at Casa Africa prepare food Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Asylum seekers of the city and a local pose for a photograph Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Maye, 24, artist from Columbia came to show her support at the celebratory lunch following news the eviction of asylum seekers had been stopped Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A member of one of Barcelona's solidarity networks Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Street view of people gathering for a celebratory lunch outside Casa Africa Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Solidarity network members and asylum seekers share a joke Anu Shukla Barcelona Refugee Squat - 'Casa Africa' One of the occupants of Casa Africa shares a joke as he serves food Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Casa Africa entrance Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Exterior of Casa Africa with a sign that says: "Property speculators and thugs get out of the neighbourhood" Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Occupants of Casa Africa share a joke during lunch after hearing the eviction was postponed Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Local community members and an occupant of Casa Africa engage in conversation Anu Shukla Barcelona Refugee Squat - 'Casa Africa' An occupant of Casa Africa serves lunch Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A sign for donations to help the occupants of Casa Africa in Catalan and French Anu Shukla Barcelona Refugee Squat - 'Casa Africa' One of the occupants of Casa Africa looks down from the balcony of the squatted building Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A Casa Africa occupant and community member swap stories about life on the roof top of the squatted building Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A couple at the protest, which was held on Friday 11 January 2019 to demand rights for asylum seekers Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Protesters at the demonstration on Friday 11 January 2019 were demanding rights for asylum seekers Anu Shukla Barcelona Refugee Squat - 'Casa Africa' People march at the protest to demand rights for asylum seekers on Friday 11 January 2019. The banner reads "Against institutional racism" Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Protesters at the demonstration on Friday 11 January 2019 were demanding rights for asylum seekers Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Mahe, 24, an artist from Columbia joined the protest on Friday 11 January 2019 to demand rights for asylum seekers Anu Shukla Barcelona Refugee Squat - 'Casa Africa' A woman shouts into a megaphone 'quemar el sistema fascista y racista' - burn the fascist and racist system, at the protest on Friday 11 January 2019 Anu Shukla Barcelona Refugee Squat - 'Casa Africa' One of the occupants of Casa Africa holds a banner at the demonstration on on Friday 11 January 2019 to demand rights for asylum seekers Anu Shukla Barcelona Refugee Squat - 'Casa Africa' An asylum seeker dances in the street during the protest demanding rights to live in the city on Friday 11 January 2019 Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Protesters at the demonstration on Friday were demanding rights for asylum seekers on Friday 11 January 2019 Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Refugees and locals join forces to demand asylum rights at a the protest on Friday 11 January 2019 Anu Shukla Barcelona Refugee Squat - 'Casa Africa' Protesters at the demonstration on Friday were demanding rights for asylum seekers on Friday 11 January 2019 Anu Shukla

Defence minister Christopher Pyne and immigration minister David Coleman also voiced their opposition to the bill.

Mr Pyne said the government would be forced to reopen a detention centre on remote Christmas Island if the bill was passed as most of the 1,000 asylum seekers in the camps would travel to Australia for medical assessment.

He said reopening the centre would cost 1.4bn Australian dollars (about £770m).

“They’ll be coming to Australia one way or the other saying that they have a need to because of ill health,” Mr Pyne said in an ABC television interview on Sunday.

Mr Coleman said the change would cause a return to the days when thousands of asylum seekers travelled to Indonesia and then paid smugglers to take them on to Australia by boat.

Many drowned when their boats got into trouble.

“We are talking about a catastrophic failure under the previous government where 1,200 people drowned at sea, where 50,000 people arrived and 8,000 children were forcibly placed into detention,” he said in a Sky News interview.

Tony Bartone, president of the Australian Medical Association, said in a statement that the government should set up “appropriate mechanisms” to allow the temporary transfer to Australia “for those in need of urgent care”.

Parliament could vote on the amendment when it resumes on Tuesday.