Rebel Nationals MP Llew O'Brien rejoins party after 10-month sabbatical

Mr O'Brien called for a spill motion during the first sitting week of the year and backed former party leader Barnaby Joyce against Deputy Prime Minister Michael McCormack.

The Queensland MP left the Nationals' party room, but not the Liberal-National Party, after the failed challenge and has effectively sat as an independent supporting the government since February.

There is speculation Mr O'Brien's return to the party is a sign another leadership challenge is brewing, however both he and the party insists everyone is united behind Mr McCormack.

"I'm definitely not going back to destabilise," Mr O'Brien said.

"I'm putting any old grievances behind me and I hope for everyone else's sake they can, too.

"I don't think I need to apologise for anything. I said what I said and was up front about it. I am actually rejoining my colleagues so we can fight for the best interests of Australians."

Deputy Nationals leader and Agriculture Minister David Littleproud welcomed his colleague back into the fold.

"If I was living in Wide Bay I'd be damn proud to have Llew O'Brien as my local member because he's all about his local community," Mr Littleproud said.

"He sits within the values and principles of the National Party. We're only worried about the bush and regional Australians, and that's what Llew does and personifies in his leadership in his local community."

A cabinet reshuffle is expected before the end of the year, and Mr O'Brien's return will give the Nationals more leverage as the internal jostling for positions begins, as the number of Coalition ministers is based on what ratio their party makes up of the partnership.

Mr O'Brien was granted an unexpected promotion when he left the party, after a handful of anti-McCormack Nationals' MPs embarrassed the government by voting with Labor and the crossbench to defeat the Coalition's nomination for Deputy Speaker, and installed Mr O'Brien.