Prime Minister Scott Morrison says he will do whatever he can to quash a multi-party push to legislate faster medical treatment for refugees on Manus Island and Nauru.
Labor and the Greens have formed an alliance with key crossbench MPs to force an end-of-year vote on the issue so the remaining 10 children on Nauru can be evacuated before Christmas.
The proposed laws, being driven by Wentworth MP Kerryn Phelps, would allow critically ill refugees to be flown to Australia for medical treatment on the advice of two doctors.
But Mr Morrison says Labor's support for the changes show the party and its leader Bill Shorten are a "clear and present threat to Australia's safety".
He says he will stop the ammendment at all costs.