Prime Minister Malcolm Turnbull targeted Senator Dastyari in Question Time on Monday over his links to Chinese Communist Party-linked political donor Huang Xiangmo, and also questioned Opposition Leader Bill Shorten's support for the embattled NSW senator.

Labor returned fire by pressing the government over whether it had ordered an investigation into a possible leak of national security information to Fairfax Media, and taunted Mr Turnbull over a photo of the Prime Minister with Mr Hunang.

In a 2015 interview with the China Economic Net website - which is designated by the Chinese government as a 'key' media outlet - Senator Dastyari is quoted as extending his "warm congratulations" to the Chinese people on the anniversary of the victory of the "Chinese People's War of Resistance Against Japanese Aggression and the World Anti-Fascist War".

Swinburne University China expert John Fitzgerald said the phrase "Chinese People's War of Resistance Against Japanese Aggression and the World Anti-Fascist War" was a "loaded term".

Dr Fitzgerald claimed Senator Dastyari would have had to learn the phrase "from people well-versed in the political ideology of the Chinese Communist Party".

"China's war of resistance against Japan - that is the term generally used in English," he said.

"He must be speaking from dot points drafted by someone with close links to the Chinese communist party or government – a minder or go-between. It is not plain English, certainly not how we remember the war against Japan in Australia. This is Beijing's officially approved language for the war of resistance against Japan."

Chinese president Xi Jinping used the term in a major speech in 2015 on the 70th anniversary of the victory over Japan.

Foreign Minister Julie Bishop told Fairfax Media that "by adopting the language of a foreign government on a highly sensitive issue, this is further evidence Senator Dastyari has been hopelessly compromised".

University of Technology professor and China dissident Feng Chongyi said the Chinese Communist Party had changed the term used for the war in 2015.

"If Senator Dastaryi used that that term than he is toeing the Chinese Communist Party line," he said.

But Senator Dastyari played down his use of the phrase, arguing it was "common usage for how victory over Japan Day is written in Chinese".

"I used the term because that is the Chinese title of the event being celebrated," he said, adding former Liberal veterans affairs minister Michael Ronaldson had attended an event in China to mark the 70th anniversary.

Senator Dastyari did not answer questions about whether he, or a staff member or associate, had provided the written response published by the China Economic Net website.

Fairfax Media last week revealed that Senator Dastyari had warned Mr Huang his phone was likely tapped by government agencies, including the US government.

Senator Dastyari was forced to step down from his job of deputy opposition whip in the Senate, but he has remained in Parliament.

Mr Turnbull on Monday asked Mr Shorten what advice he had given Senator Dastyari about Mr Huang that prompted him to go to Mr Huang's house "and tell him how to avoid surveillance activities by ASIO".

"After briefings to the political leadership of the Labor Party, Senator Dastyari comes to the view that his patron, Mr Huang, might be under surveillance from ASIO. Off he goes to Mr Huang's house and he tells him to take care and to have a conversation in the garden with the phones put safely inside. That's not the conduct of a loyal Australian," the Prime Minister said.

Labor MPs are divided over whether the NSW senator should resign from Parliament. There is a consensus view that one more revelation about Senator Dastyari could spell the end of his parliamentary career.

As one put it to Fairfax Media on Monday: "The problem for Sam is that every time you look at him you see someone who has been an agent of foreign influence - and you can't have an agent of foreign influence sitting in the Senate".

Other MPs disagreed, arguing the senator had already paid a heavy price.