Retiring Victorian independent MP Cathy McGowan is tight-lipped on whether she will support legislation designed to get sick asylum seekers off Manus Island and Nauru.
Ms McGowan, who is leaving politics at the next election, could spare the federal government from a humiliating defeat on the floor of parliament by voting against the bill.
She will meet Prime Minister Scott Morrison in Sydney on Tuesday to discuss a range of issues affecting regional Australia.
While the medical transfer bill is not listed as a topic for their discussions, Ms McGowan expects it is likely to come up.
Ms McGowan declined to say whether she would vote for the legislation when parliament returns in February.
"Getting the kids off, having people treated well, I have voted strongly the whole time I have been in parliament with that agenda," she told ABC Radio National on Tuesday.
"When the bill comes up to parliament I will vote on it in the normal way, and I am not going to do it now in the media."
The bill would compel immigration ministers to more readily approve medical evacuations from Manus Island and Nauru based on advice from two treating doctors.
The government has argued it would undermine Australia's border protection policies by removing from ministers the final say on who comes to the country.
The changes will come into effect if Ms McGowan sides with fellow independents Rebekha Sharkie, Kerryn Phelps, Julia Banks and Andrew Wilkie to vote with Labor and the Greens.
However, if Ms McGowan or another crossbencher turned their back on the bill, its passage would be in doubt.