Labor and the Greens have accused crossbench senator Jacqui Lambie and the Government of striking a secret deal to end the medevac laws that allow refugees to come to Australia for medical treatment.

Key points: The Senate votes 37-35 to repeal medevac laws, with Jacqui Lambie, One Nation and Cory Bernardi's support

The Senate votes 37-35 to repeal medevac laws, with Jacqui Lambie, One Nation and Cory Bernardi's support The laws allowed doctors more control to bring refugees in PNG and Nauru to Australia for treatment

The laws allowed doctors more control to bring refugees in PNG and Nauru to Australia for treatment Senator Lambie and the Government have refused to reveal the details of their negotiations

The Tasmanian senator, who held the crucial vote on the proposal, has repeatedly refused to outline the details of her negotiations with the Coalition, insisting it was a matter of national security.

Her vote gave the Coalition the numbers it needed to repeal the laws, which passed the Senate on Wednesday morning.

"I am voting for the repeal of medevac because I am satisfied that the conditions that led to medevac being passed aren't the same as the conditions today," she said.

"The world in which this vote takes place is different and I thank the Government for working productively with me to make sure of that."

The medevac laws, which give doctors more power to decide whether refugees on Papua New Guinea and Nauru should come to Australia for treatment, came in under the previous Parliament, when the Coalition was governing in minority.

The Coalition also gained the support of One Nation and soon-to-retire senator Cory Bernardi to win the final vote 37 to 35, with Labor, the Greens and Centre Alliance opposed.

"At the moment we have cabinet ministers like lemmings coming in here to vote for a bill on a deal you haven't seen," Labor's Penny Wong told the Senate.

"That's how cabinet government works in this country — members of the cabinet of Australia are coming in to vote on a deal that's been done with Senator Jacqui Lambie that they don't even know about.

"What sort of cabinet government is that? What sort of process of democracy is that?"

Penny Wong accused the Government of hiding a secret deal with Jacqui Lambie to end medevac. ( ABC News: Mark Moore )

Labor and the Greens demanded the terms of any deal be made public before the Senate votes on repeal legislation to overturn the laws.

"Let me just make the most important point right up front — there is no secret deal," the Government's leader in the Senate, Mathias Cormann, told the Parliament.

"Let me repeat that again. There is no secret deal."

Lambie cites national security as she keeps talks secret

Senator Lambie, who fought back tears as she spoke in the Senate, appeared to offer a different account to Senator Cormann.

She said her negotiations with the Government had satisfied her to support repealing the laws.

"I put up to the Government a proposal to work with me on to secure my support for the passage of the repeal of medevac," Senator Lambie said.

"I'm not being coy or silly when I say I genuinely can't say what I proposed.

"I know that's frustrating to people and I get that. I don't like holding things back like this. But when I say I can't discuss it publicly due to national security concerns, I am being 100 per cent honest to you."

Jacqui Lambie became emotional as she confirmed her support for the repeal of medevac. ( ABC News: Mark Moore )

That prompted a rebuke from Greens leader Richard Di Natale, who accused either Senator Lambie or Senator Cormann of misleading the Parliament.

"We had Minister Cormann say that there was no deal. Now we've just heard Senator Lambie say there is a deal," Senator Di Natale said.

"Who's lying? Who's lying? Minister Cormann, are you lying? Or is Senator Lambie lying?

"We've just heard that you and Senator Lambie have worked on a secret proposal, in good faith that she cannot disclose for so-called national security reasons."

Speculation of a deal to settle in New Zealand

Shadow Home Affairs Minister Kristina Keneally questioned whether Senator Lambie had asked the Government to accept a resettlement offer from New Zealand, as reported by Channel Nine last week.

"If the Prime Minister has done a backflip, if he has decided to accept New Zealand's offer to take refugees on Manus and Nauru, that is a change in policy, he should announce it to the Australian people," she said.

"And frankly it's a change in policy Labor would support. So I think it's incumbent now upon the Prime Minister to explain what he has done."

Senator Lambie has refused to comment on whether New Zealand resettlement was part of her negotiations.

Prime Minister Scott Morrison would not be drawn, and left open the prospect that Australia would agree to the New Zealand offer, after a resettlement deal with the United States was completed.

Mr Morrison dismissed suggestions there was a secret deal with Senator Lambie and said the only assurances he had offered was that the Government would implement its policies.

"I thank [Senator Lambie] very much in the way that she has worked with us to get through the issues and enable us to shut the door that Labor sought to prise open last year," Mr Morrison said.

"They sought to prise open the door on Australia's border protection regime because they've never ever believed deep down in the border protection policies that the Government has put in place.

"The biggest myth running around this place in Australian politics over the last decade is that the Labor Party supports the Government's border protection's policy. They simply don't."

Pauline Hanson spoke with Coalition frontbencher Anne Ruston before backing the repeal of medevac. ( ABC News: Mark Moore )

One Nation leader Pauline Hanson dubbed the medevac laws "ridiculous" and something her party was eager to repeal.

She took aim at Labor, accusing the Opposition of being hypocrites for criticising Senator Lambie and the Government.

"I will not sit here and listen to the Labor Party, greater than all thou, as if they've never done their deals," Senator Hanson said.

"They're a bunch of hypocrites because when you're in government, you will deal with whoever you can to actually get your legislation through."

The Human Rights Law Centre said the medevac repeal had created uncertainty and anxiety for the asylum seekers and refugees on PNG and Nauru.

The Law Centre's David Burke said allegations of a secret deal added to the confusion.

"What is the Government's plan for those people?" he said.

"Whether it's part of this deal or not, they've spent six years in offshore detention. We are terrified about what the consequences of this repeal is."