Senator Brian Burston has quit the One Nation party following weeks of bitter words with leader Pauline Hanson over his decision to back the government’s company tax cut.

Senator Burston confirmed his resignation on Thursday, thereby stripping One Nation of its balance of power in the Senate. The minor party is left with just two members as the government builds its numbers in the upper house for crucial votes over the next two weeks.

“It is with a heavy heart that I announce that I am resigning from Pauline Hanson’s One Nation Party,” he said in a statement.

“It has become clear to me that my relationship with Senator Hanson is irrevocable.

“The best way forward for me to represent the best interests of the constituents of NSW with honour and integrity is for me to resign from [One Nation].”

NSW constituents would be best represented by his resignation from the minor party, he said.

Senators Burston and Hanson had been publicly trading barbs since Senator Hanson removed him as the party’s whip last month.

She accused him of “stabbing her in the back” over company tax cuts and trying to defect to another party, before asking him to resign two weeks ago.

Senator Burston is the third One Nation senator to quit in this term of Parliament, following Rod Culleton and Fraser Anning.

He also urged Senator Hanson’s last remaining parliamentary colleague, Peter Georgiou, to follow him out the door.

“I think it should be called Gone Nation instead of One Nation,” he said.

“There is no democracy in the party – every single decision made is made by Pauline Hanson, and if you don’t agree then you’re gone.”

Senator Georgiou last week insisted he will stay loyal to Senator Hanson, rejecting claims his leader is autocratic amid internal divisions.

“With Burston, hopefully things can get sorted out. But I’m the last man standing for now. I’m a One Nation senator and I intend to be a One Nation senator at the next election,” the WA senator was quoted as saying by The Australian.

Prime Minister Malcolm Turnbull said the government would continue to convince crossbenchers to back legislation whichever party they belonged to.

“We treat all senators with the greatest of respect regardless of their party or their affiliation,” Mr Turnbull told reporters in Hobart on Thursday.

-with AAP