Party now has same influence as Centre Alliance and the crossbenchers who have formed a loose voting alliance

Pauline Hanson has officially lost her balance of power in the Senate, with her estranged New South Wales senator Brian Burston announcing that he has quit the party.

Relations between Hanson and her former loyalist and longtime friend Burston began to sour, for the second time, earlier this year, when Hanson anointed Malcolm Roberts as her Queensland Senate pick but said Burston would have to reapply for his Senate position “like any other candidate”.

In announcing his resignation, Burston said the relationship breakdown with Hanson was “irrevocable” and his best way forward was as an independent.

Asked about the party breakdown at his morning press conference, Malcolm Turnbull said his government would continue to work with all the crossbench, no matter how it’s made up.

“I’ll leave the commentary to you, but as my senatorial colleagues here know, and they work very hard to, you know, get the support of the crossbench to our legislation, we treat all senators with the greatest of respect, regardless of their party or affiliation, and we seek their support for our legislation and we have over the last few years had a great deal of success,” he said.

The first public indication that something was amiss came when Burston was dumped as party whip in May. That month he stripped his social media presence of One Nation branding and announced that he would still vote for the government’s company tax cuts, despite Hanson’s proclamation she would be reneging on the deal she had struck with the finance minister, Mathias Cormann.

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In a live interview on Sky News, Hanson cried as she said she had been betrayed by Burston, after being told he had made an approach to join the NSW Shooters, Fishers and Farmers party. She declared that Burston would not “finish her” and she “will win”.

Burston maintained that a constituent had made the approach on his behalf, without his knowledge. But he learnt on a live radio interview with 2GB that Hanson had expelled him from the party executive and had written to him demanding he quit the party, and the Senate, so One Nation could take the seat back.

It was then that Burston accused Hanson of running a “dictatorship”.

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“She is saying she’s no longer got the confidence I’ll agree with every single decision she makes, as president for life,” he said at the time. “I thought I joined One Nation as a democratic political party, not a dictatorship.”

Burston announced his official resignation through Fairfax Media and confirmed to Guardian Australia on Thursday morning.

It is the second time Hanson has fallen out with Burston over One Nation. Burston was part of the first incarnation of the party two decades ago but was sacked, along with David Oldfield, in the late 1990s over what he called “internal issues”. The party fell apart soon afterwards.

His move strips Hanson of her Senate balance of power, with her voting bloc now just numbering two, giving One Nation the same influence as Centre Alliance and a number of crossbenchers who have formed a loose voting alliance.

Since bursting onto the political scene in the late 90s, One Nation has had 30 people elected under its banner across Australia’s state and federal parliaments. Of that number, 22 have quit the party, or parliament, been disqualified or forced from the party before their term expired.

The government needs eight of the 10 crossbench votes if Labor and the Greens reject its legislation.

