The government sought to end a six-week stalemate over who should be president of the upper house by installing their preferred candidate, even though she failed twice to capture a majority of votes.

Liberal Natasha Maclaren-Jones’ tenure in the seat was short-lived and chaotic.

After failing to bring the MPs to order and struggling to be heard over shouts of “You are not elected”, she was toppled by a vote of no confidence after just 90 minutes in the chair.

“This is the world's worst coup,” Greens MP David Shoebridge said during the heated debate.

Several members called the proceedings a “disgrace”.

The debate descended into name-calling, with Labor MP Anthony D‘Adam calling One Nation’s Mark Latham a “fascist” and the latter saying the Labor member was a “parent-hater”.

Mr Latham, who supported Ms Maclaren-Jones as president, called the opposition’s defiance a “ridiculous circus”.

He was joined by Christian Democratic MP Fred Nile in backing the government’s choice.

Liberal MP Catherine Cusack said she also supported the pick, but said the way Ms Maclaren-Jones was installed was a “fiasco”.

“I personally do not support the tactics that the government employed tonight in an effort to impose my friend the honourable Natasha Maclaren-Jones as president of the house,” Ms Cusack said.

She has previously taken a rebel stance against government legislation and been punished by the NSW Premier for it.

“I actually have no clue as to what people were thinking by using that strategy. It was unsustainable and not consistent with the dignity of this house,” Ms Cusack continued.

“It certainly did my friend and colleague the honourable Natasha Maclaren‑Jones no favours whatsoever.”

While Ms MacLaren-Jones got the most votes out of anyone in a pair of back-to-back ballots in late March, she failed to capture the majority of votes.

MPs then sought legal advice as to whether that meant she was still the legitimate winner.

After receiving two separate legal opinions that were both in the government’s favour, the Liberal leader of the upper house decided on Tuesday evening to ask Ms Maclaren-Jones to take the president’s chair.

But Labor, backed by the Greens, the Shooters, Fishers and Farmers’ party, and an independent MP, refused to accept it, arguing Ms Maclaren-Jones should not be president because did not have the support of the majority.

Labor MPs have previously said they weren’t convinced Ms Maclaren-Jones would be able to maintain the chamber’s independence and thought she would be beholden to Premier Gladys Berejiklian.

Upper house opposition leader Adam Searle immediately moved a motion to remove her. The motion passed 22-16 and Ms Maclaren-Jones’ reign was over.

Later in the evening, the upper house finally got its president. Liberal MP Matthew Mason-Cox won a ballot by 23 votes to Ms Maclaren-Jones’ 18 votes and assumed the chair.

“I express my profound thanks and gratitude for the confidence that is reposed in me,” he said in his first remarks as president.