"They are all issues to be discussed," he said.

"If there were to be additional members, as a part of our team, that certainly strengthens our entitlements in relation to the ministry and naturally we would expect those elements of the (Coalition) agreement to be honoured."

Such a move could risk a civil war within the Coalition with many Liberals dismayed at Mr Macfarlane's move.

While the Nationals party room rubber stamped the defection on Thursday, it was not without rancour. Several younger Nationals protested Mr Macfarlane could not just join the party and go to the front of the queue for the next ministerial promotion.

The move also complicates the finely balanced numbers over who will replace Mr Truss as leader. About half the party backs Barnaby Joyce and the other does not. Mr Macfarlane is seen as a vote against Mr Joyce. He is not interested in a leadership role himself, he said.

The defection must still be approved by the Liberal-National Party branches in Mr Macfarlane's Towwomba-based seat of Groom.

All Queensland federal Coalition MPs belong to the Liberal-National Party but align themselves in Canberra with either the Liberals or the Nationals.

Although he was close to Mr Turnbull and supported the ousting of Tony Abbott, Mr Macfarlane lost his cabinet job because of Mr Turnbull's desire for renewal.


He had been on the Coalition frontbench since John Howard first made him a minister in 2001.

Mr Truss revealed that Mr Macfarlane approached him"a few days" after the new cabinet was announced and was "angry and upset" at being dumped.

Mr Buchholz lost his job as government Whip when Mr Abbott fell.

Mr Macfarlane said on Thursday he was willing to serve in the ministry again and, pointedly, said the next promotion from the Nationals should be merit based.

"I'll be considered on my merits along with all the other members of the National party if a ministry becomes available," he said.

"Of course I'll be putting myself forward if a vacancy becomes available but it will be decided on merit."

The Nationals led the way in helping tear down Mr Turnbull's leadership in 2009 when the revolted against plans to support Labor's carbon pollution reduction scheme. Relations between the Liberals and Nationals because so tense the Coalition was on the brink of splitting when Mr Turnbull was deposed.

There were ominous signs earlier this week when Mr Macfarlane and the Nationals combined to pressure Mr Turnbull to back away from signing a communique on fossil fuel subsidies at the Paris climate change talks because they believed it would pose an eventual threat to the diesel fuel rebate.


The federal Nationals are also gearing up to stop the federal Liberals trying to wind back a vote of the Queensland Parliament to re-regulate the sugar industry on the basis the move contravenes Australia's international trade obligations. The Queensland Labor government failed to defeat the move which ewas backed by state Nationals and independents.

It now becomes a problem for Foreign Affairs Minister Julie Bishop and Trade Minister Andrew Robb.

Mr Macfarlane's defection has angered Queensland Liberals who will have their power base eroded.

"Weak as piss," said one MP.

Queensland Liberal Steven Ciobo said Mr Macfarlane was motivated by trying to rekindle his ministerial career.

"People will see it for what it is," he said.

"He views it as his pathway back into the ministry."

It came at the end of a messy week in which the government was on the back foot defending Special Minister of State Mal Brough.


Mr Macfarlane has been a Liberal since he entered Parliament in 1998.

Mr Macfarlane visited Mr Turnbull on Wednesday to inform him of his plans and it ius understood Mr Turnbull was nt happy. The Prime Minister is yet to comment publicly on the defection of the man who did the numbers for him in 2009 when he lost the leadership to Mr Abbott.

One Nationals MP who supports the defection said Mr Macfarlane was a welcome addition and should go to the front of the queue for the ministry.

"We need to strengthen our team."

Mr Macfarlane has a strong rural pedigree. A farmer, he has held the Toowoomba based seat of Groom since 1998. Prior to that, he was president of the Queensland Grain Growers Association.

Mr Macfarlane said he had a natural affinity for the bush. He already owns five Akubra hats and seven pairs of RM Williams boots, he said.