The opposition would not back ratification of the treaty; China would not be added as "an extradition country" under the Extradition Act.

Ten minutes later, Mr Turnbull called Mr Shorten back. Without Labor, the treaty could not be ratified. Instead, he would pull it from Parliament.

Two phone calls and 10 minutes decided it.

But the political danger the extradition treaty posed for the Turnbull government had been hiding in plain sight for months.

And the government's handling of the matter has prompted fresh questions about its processes and political radar.

Signed by John Howard back in 2007, but never ratified by successive governments, the treaty is supposed to facilitate the two nations being able to return an accused criminal to the other country to face trial.

During hearings late last year, the Law Council of Australia, Amnesty, Labor and the Greens all flagged concerns about the treaty's safeguards to ensure people sent back to China would not face the death penalty or torture, and get a fair trial.

But it wasn't just legal and rights groups and opposition parties who were concerned. At a November 24 hearing, Coalition MPs Chris Crewther and Andrew Wallace also raised concerns.

Mr Wallace asked the Attorney-General's Department: "How could we as a government be assured that, apart from the fact that an undertaking from one government to another government is very important ... it [the death penalty] will not in fact be carried out and hidden from us?

First assistant secretary Anna Harmer responded: "It is fairly critical that there be an ability to rely on the assurances that have come [from China]. It would be quite extraordinary if a country were to breach an undertaking that it had made on a government-to-government basis."

In other words, the Australian government would simply have to trust the Chinese government.

"And given that it has been in limbo for the last nine years, who or what department, if any, is driving that this be ratified now?" Mr Wallace asked.

Liberal MP Stuart Robert, the committee chair, answered: "It is a referral from the foreign minister to the chair of the committee in writing."

The government missed the early signs from these two backbenchers and pushed on, tabling the treaty on March 2 ahead of Chinese Premier Li Keqiang's visit, giving the Senate or the House 15 days to disallow it.

Then things really started to come unstuck.

On March 21, Senator Bernardi told Fairfax Media there was "no public case to justify" ratification. Then he announced he would try to disallow it; Labor, the Greens and the Xenophon trio indicated they would join him.

No one from the government spoke to Senator Bernardi about his plan, despite the gathering storm.

Calls were made at the highest levels of government to the opposition, attempting to rally support.

At the same time, disquiet in Liberal Party ranks grew too; as one MP put it: "We should be deporting their spies, not extraditing their dissidents."

On Monday night, two crucial things happened: Labor's shadow cabinet resolved to oppose ratification and Ms Bishop and Mr Keenan briefed a dozen Coalition MPs who were unhappy with the treaty.

Labor's decision, backed by caucus, ensured the treaty could not be ratified and gave the Prime Minister the public reason to withdraw it.

But the Liberals who attended the briefing, some already muttering about crossing the floor, were the real concern.

Once again, the Turnbull government had scored an avoidable own-goal; senior ministers who publicly backed the treaty on Tuesday morning, before the decision was taken were left hung out to dry; backbenchers came away furious with the process, and the fact that they had been pushed to the point where they could have crossed the floor; and Australia's major trading partner became the subject of a messy public debate only to be left empty-handed.

On Tuesday evening, Liberals were still scratching their heads and asking why the government had ever brought it on at all.

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