IAN Macfarlane made the announcement he was quitting politics after his failed bid to defect to the Nationals in December.
The defection attempt came after he lost his position as Science and Industry Minister in September's cabinet reshuffle to Christopher Pyne.
He had backed Prime Minister Turnbull against former PM Tony Abbott in their leadership tussle and was surprised when he was dumped as minister.
The party defection was touted as a way for Mr Macfarlane to return to the front bench and bolster the number of Nationals members in the Lower House.
"I'd be considered on my merits along with all the other members of the National Party if a ministry becomes available," he said.
At the time Mr Turnbull had said the Groom MP wasn't sacked because he'd been a poor performer.
"It was because I wanted to make room for new people, for younger people, for more women," he said.
"There are only so many places in the Cabinet and you cannot bring new talent up unless some of the older talent moves on.
"I give the example of Gail Kelly, former CEO of Westpac.
"Gail could have run Westpac for another decade or two, but she moved on because other people had to move up. So you've got to have succession."
Mr Turnbull maintained the Coalition was not divided despite the public feud.
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