PM courts China extradition deal support

Prime Minister Malcolm Turnbull is urging the opposition and crossbenchers to support an extradition treaty with China, as the deal hangs in the balance.

The treaty could be shot down in the Senate through a looming disallowance motion, with Labor keeping its cards close to its chest and the Greens plainly opposed.

"There are very considerable protections in the treaty and it is an important part of our cooperation with China on law enforcement," Mr Turnbull told reporters in Canberra on Monday.

He pointed to a $100 million methamphetamine bust as proof of the two countries' crime-fighting ties.

"Had it not been for that cooperation, (those drugs) would have been on the streets in Australia, destroying Australian lives."

Labor leader Bill Shorten said the opposition was considering the treaty very carefully, saying it went to questions of Australia's relationship with China, human rights and the rule of law.

"Our party will be discussing this matter in the coming days before the vote," he said.

"Suffice to say, though, we think the extradition treaties which the government of Australia has signed up to around the world need a review and that's certainly where some our thinking is at the moment."

The Greens will vote to block the treaty.

"The Chinese government's legal system quite frankly cannot be trusted," Greens justice spokesman Nick McKim said.

"The conviction rate is astronomical, which calls into significant question someone's right to a fair trial in China, and we will not be supporting the extradition of Australians to China."

While he was not across the details, the case of Sydney academic Chongyi Feng, who has been stopped from returning to Australia, added weight to those arguments.

"We've had a look at a number of past cases, we've had a look at the record of the Chinese so-called judicial system over there, and we simply don't trust it."