Scott Morrison warns of 'weaker borders' after medivac bill is passed

Doctors visited Parliament House to urge politicians to back a bill to make it easier for critically ill asylum seekers to be transferred to Australia

The changes were part of the Urgent Medical Treatment Bill, the passage of which marked the first time in 90 years an Australian government had lost a substantive vote in the house.

But the 75-74 vote - which came on the first sitting day of Parliament this year - in favour of the refugee Bill opposed by the government is a blow to the already embattled Prime Minister and raised questions about whether he can remain in office.

His coalition has to call an election by May and has been trailing the opposition centre-left Labor Party in opinion polls.

Prime Minister Scott Morrison said a security committee of his cabinet agreed to reopen the camp on Wednesday on the advice of senior security officials.

Immigration policy requires asylum seekers intercepted at sea to be sent to camps in PNG and its northern island of Nauru, and they can not set foot in Australia, even if they are found to be refugees.

The detention centre on Christmas Island will reopen, the federal government announced.

Phil Glendenning, President of the Refugee Council of Australia said, "We thank and congratulate all the Members of Parliament and Senators who came together and voted with their conscience on this long overdue legislation".

The push to speed up medical evacuations was first made by independent MP Kerryn Phelps previous year after she won the Liberal Party stronghold of Wentworth when former PM Malcolm Turnbull was ousted in a party coup.

Morrison said he would repeal the "foolish law" if his government were re-elected.

Under a harsh policy meant to deter asylum seekers from reaching Australia by boat, Canberra sent arrivals to Nauru and Papua New Guinea for processing and barred them from resettling in Australia.

The vote has paved the way for border protection to be a major issue in the general election, which Morrison on Tuesday said would be held in May despite the historic defeat.

Labor leader Bill Shorten says his party is tough but fair on border control after it backed the bill. "This puts Australia back on the map for people smugglers and Bill Shorten has that on his shoulders".

"This is merely codifying something that the government itself says is happening now". "This is a turning point for the people on Manus Island and Nauru, who for too long have suffered both mentally and physically without access to adequate medical facilities and the care they needed".

"Under my government Australia will be stronger".

"I know how much the people who are sick on Manus Island and Nauru are suffering and Parliament is saying enough is enough,"Dr Phelps said after the vote".