Queensland MP Llew O'Brien has quit the Nationals party room.

Key points: Llew O'Brien moved the spill motion which brought on last week's leadership spill

Llew O'Brien moved the spill motion which brought on last week's leadership spill He will remain a member of the Queensland LNP, and will support Prime Minister Scott Morrison and the Government

He will remain a member of the Queensland LNP, and will support Prime Minister Scott Morrison and the Government His departure means Barnaby Joyce is down one of his chief backers should he try to challenge for the Nationals leadership again

But in a shock move late on Monday, he won a promotion after Labor successfully conspired to elevate him to become Deputy Speaker in the House of Representatives.

The backbencher has been a vocal supporter of former leader Barnaby Joyce, and moved the spill motion which allowed Mr Joyce to challenge leader Michael McCormack in the Nationals party room last week.

That challenge from the former deputy prime minister ultimately failed.

Mr O'Brien has been outspoken on a number of policy issues, including a stronger national integrity commission.

He will remain a member of the Liberal National Party in Queensland and has told Prime Minister Scott Morrison he will continue to offer the Government support.

"When Queensland LNP members come to Canberra they sit in either the Nationals party room or the Liberal party room. However, my decision today means that I am seeking to not sit in either party rooms," Mr O'Brien said in a statement.



"As a member of the LNP, I will remain in the Liberal and Nationals joint party room, meaning I will remain a Government member."

O'Brien becomes Deputy Speaker

Mr Morrison's minor frontbench reshuffle last week included the promotion of Nationals MP Kevin Hogan, who had been the deputy speaker, to an outer ministerial role.

The Government planned to replace him with Victorian Nationals MP Damian Drum.

But when the Lower House went to vote on the matter, Labor nominated Mr O'Brien.

Mr O'Brien accepted the nomination and won the ballot 75 votes to 67.

The promotion means Mr O'Brien will receive a 20 per cent increase in his base wage of $211,250.

Joyce wants O'Brien in the Nats

His preferred leader Mr Joyce said he had discussed the matter with Mr O'Brien but refused to outline what the pair said.

"I'm going to keep my conversations with Llew O'Brien to myself," Mr Joyce told the ABC.

"It's not for me to speak for another person.

"It's incredibly sad, Llew is — we want to keep him in the team, a former vice president of the LNP, a person with so many years experience serving in the police force."

The Queensland police officer changed careers in 2016 when he won the federal seat of Wide Bay, which was previously held by former Nationals leader Warren Truss.

The relatively unknown backbencher has made headlines on a handful of occasions, when he has caused headaches for his own party.

He previously threatened to cross the floor when the then-Turnbull government did not support the establishing of a banking commission of inquiry.

His decision to quit the party is similar to that of Nationals MP Kevin Hogan, who moved to the crossbench after Malcolm Turnbull was rolled as prime minister — complaining the office had become a "revolving door".

Finance Minister Mathias Cormann downplayed the significance of Mr O'Brien's decision.

"He continues to serve as a member of the LNP, he continues to sit in our joint party room, and he continues to support the Government," Senator Cormann said.

"So, business as usual."