Senior federal ministers are closing ranks around the first-term federal MP who is facing calls to "consider her tenure" over her connection to several Beijing-linked groups.

Ms Liu is also under pressure after failing to properly declare an almost $40,000 donation to the Liberal Party, and waiting almost three years before declaring another $25,000 gift.

The prime minister says there's a "grubby undertone" to the reports.

He also posted a clip of his parliamentary defence of Ms Liu on Chinese-language social media WeChat with the comment in Mandarin: "The Labor Party is sparing no effort to discredit Liu but I will stand up and defend her and all Australian Chinese because they have made great contributions to Australia with a sincere heart".

But asked point-blank whether he was saying Labor's pursuit of Ms Liu was racist, he said he would leave it to others to draw the conclusion.

His Attorney-General Christian Porter labelled the hounding xenophobic.

Opposition Leader Anthony Albanese said Labor's only motivation was ensuring accountability.

"It has nothing to do with race and the only person who has raised race in these issues is, of course, Prime Minister Morrison," he told reporters in New Zealand.

"The same guy who labelled (former Labor senator) Sam Dastyari as 'Shanghai Sam' repeatedly in the parliament."

Mr Morrison used the disparaging nickname several times in 2017, including during question time when he was cautioned by the Speaker for it.

In another instance, he used it in a speech to the Liberal Party's federal council, and in an interview on Sky News that he later posted to his personal Facebook page with the comment "Shanghai Sam must go".

On Friday he was asked why it was racist to question Gladys Liu's connections to China but not racist to call Mr Dastyari 'Shangahi Sam'.

"I didn't use either of those phrases. I think people here today are focused on the fires not Canberra," he told reporters in Queensland, where he met with volunteer firefighters.

Later he rang into radio station 2GB to say he heard the word "racist" twice in the question and reacted to it.

"Of course I remember saying Shanghai Sam," he said, adding he had no regrets about repeatedly using the nickname.

But Mr Morrison reiterated his view Labor was making a "broader smear" on all Chinese-Australians.

"They can keep making their points but I'm not going to let them off the hook about the inferences they're making and the insult that they're making to millions of Australians," he said.

Host Ben Fordham protested: "But they're only making it about Gladys Liu."

"No, I'm sorry mate, I think Labor knows what they're doing here and I've called them out," the prime minister said.

Labor's foreign affairs spokeswoman Penny Wong said Mr Morrison was hiding behind the entire Chinese-Australian community to avoid saying why he had ignored warnings from national security agencies.

It has also emerged intelligence agencies warned former prime minister Malcolm Turnbull against attending a 2018 fundraiser with associates of Ms Liu.

Separately, there are reports security agencies warned the Liberal Party not to preselect her as a candidate.

Home Affairs Minister Peter Dutton insisted there was no "smoking gun" or national security risks.

"If the prime minister or I had concerns about Gladys Liu we wouldn't be backing her the way we are," he told the Nine Network.

Australian Associated Press