Malcolm Turnbull is not the first prime minister to accuse his political opponents of putting national security at grave risk – and he certainly won’t be the last.

But Labor senator Sam Dastyari’s dealings with a Chinese billionaire are proving too good an opportunity to pass up.

Especially as the Coalition government – despite a huge boost at the weekend with Barnaby Joyce easily winning the New England byelection – is ending a very messy year precisely where it began it. The latest average of the published opinion polls has the government trailing Labor by six points. Enough to see it lose up to 13 seats and power.

This entrenched poll malaise has Coalition backbenchers worried. The Nationals are in near panic and still determined to be more assertive about their identity separate from the Liberals.

That tug-of-war is still to be played out. Although seeing Mr Turnbull basking in the reflective glory of his sidelined Deputy Prime Minister, would have you believe it is all plain sailing from here.

It does appear Mr Joyce’s historic win generating a record swing to an incumbent government’s candidate in a byelection did convince one restive Nationals MP not to desert the ship.

George Christensen fessed up that he was the unnamed MP who said he would go to the crossbench this week.

His lying denials to the media evidently worth it in forcing the Prime Minister into a humiliating reversal over a banking royal commission.

This context goes a long way to explain why the Prime Minister is so keen to inflate the Dastyari dealings into a security crisis. Never mind that to do it he himself suggested that donor Huang Xiangmo has “very, very close links to the Chinese government”.

Huang Xiangmo (second from left) with Ernest Wong, former prime minister Julia Gillard and Sam Dastyari. Mr Huang has provided large donations to the major political parties. Photo: Supplied/ABC

The Labor senator’s “treason” is telling the businessman he may be under surveillance. A fair bet given that ASIO itself has made no secret of its concerns over Chinese peddling of influence through political donations. Mr Huang has given close to a million dollars to both sides of politics.

Labor asked Mr Turnbull if he had ordered an investigation into how Senator Dastyari’s meeting with Mr Huang at his home was leaked to the media. It pointed the finger at a minister or their staff. Mr Turnbull avoided answering the question.

Labor also seized on The Daily Telegraph reporting that Mr Huang’s “right hand man” Tim Xu was in the room when the Labor senator came calling and that he is now a Liberal campaign worker in Bennelong.

Labor’s Mark Dreyfus asked “what else have Mr Huang and his associates given to the Liberals to help keep the Prime Minister in his job”, and is this one of the reasons why legislation banning foreign donations had been delayed?

Again, no answer but Mr Turnbull is promising to bring in legislation this week. Certainly too late to stop any Beijing-inspired generosity in the byelection.

It is not at all clear that Mr Xu is the source of the original Fairfax story. He was constantly at non-English speaking Mr Huang’s side as his translator. He would have needed to go outside with the senator and his boss and would certainly know what transpired between them, unlike ASIO’s eavesdroppers.

Perhaps it was no more than Senator Dastyari has admitted to, namely he was ending their association. The senator, who is not a senior government minister nor even a relevant shadow minister, says he did not pass on any classified information because he doesn’t have any.

The Chinese voters are around 30 per cent of the Bennelong electorate. We’ll find out what they think on December 16.

Paul Bongiorno AM is a veteran of the Canberra Press Gallery, with 40 years’ experience covering Australian politics.