Labor frontbencher Tony Burke today said Morrison was attempting to argue the new medical transfer system, yet to be approved by the Senate, would encourage more asylum seekers.
However, Burke noted the changes accepted by the House only applied to the 1000 refugees currently on Manus and Nauru — a provision Labor insisted on inserting during negotiations with the Greens.
"He's saying there is a benefit (for future detainees) and there is not," Burke told ABC radio.
He accused the Prime Minister of spreading "inaccurate information" to support a claim people smugglers were being sent a signal to restart business.
"The only signal that would be going there would be if the Government decided to trumpet one," Burke said.
The Prime Minister says his conclusions are based on advice from the Border Force and ASIO, which states that potential illegal immigrants "will probably be interested in any perceived or actual pathway where resettlement in a Western country is guaranteed, even if such a pathway includes a period spent in detention".
Morrison says Labor's claim that the legislation would only apply to people currently on Nauru and Manus Island - not new arrivals - cannot be trusted, and that Shorten would face pressure to make the change permanent should he win government.
Morrison said the Government would continue to fight to prevent yesterday's amendments from becoming law, and launched an immediate counter-attack on Labor's border protection credentials.
"Votes will come and they will go, they will not trouble me," he said.
"What happened in the Parliament ... was proof positive that Bill Shorten and the Labor Party do not have the mettle, do not have what is required and do not understand what is necessary."
The Prime Minister said there were "contingency plans" in place to prevent the weakening of Australia's border protection regime after the passage of the bill.
"I'll have more announcements about steps the government will be taking to address the risks that Labor have created," he said.
He rejected any suggestion the government had lost the Parliament's confidence, and dared Labor to move a no-confidence motion.
"If the Labor Party want to move such a motion, then they are welcome to do so, and it will fail," Morrison said.
"How do I know that? Because the independents have made that very clear.
"These are not matters that go to issues of confidence. I don't consider them in those terms. The government has never put them in those terms."
Home Affairs Minister Peter Dutton echoed Morrison's remarks, warning Australia would see a "return of the boats" under the Opposition.
Dutton warned the nation would face growing numbers of asylum seekers on our shores after the medevac bill passed through parliament.
"It's very clear that an unscrambling and dismantling of Operation Sovereign Borders is going to see, I think, a return of boats. It's going to see people going back into detention," Dutton said.
He slammed Shorten as "reckless" for supporting the bill, warning it would see "people come to our country who have serious allegations against them".
"What Bill Shorten supported in the Parliament yesterday is a green light for people smugglers," Dutton said.
"It's on Bill Shorten's shoulders, the first boat that arrives and the ones that arrive thereafter."
The refugee transfer bill has specific measures in place to address security concerns.
Under the legislation, the Home Affairs minister can reject the transfer on national security grounds, or if the person has a substantial criminal record and poses a threat to the Australian community.
If the minister refuses the transfer for any other reason, the decision is referred to the eight-member Independent Health Advice Panel.
The panel can then reassess the reasoning before choosing whether to make a second recommendation for transfer.
HOW THE LEGISLATION WORKS
• Two doctors would assess requests for medical transfers of people on Manus Island and Nauru. That would not include new arrivals
• The Home Affairs minister would decide whether to agree to a medical transfer
• The minister can reject the transfer on security or criminal grounds
• If refused, the decision goes to a eight-member Independent Health Advice Panel
• It can make a second recommendation for transfer
