Liberal frontbencher Nick Minchin has confirmed he will quit the Senate next year, and hand over his portfolio immediately.
"Having served nearly 17 years in the Senate, and having worked in the Party's professional arm for 14 years before that, I consider it is now time to bring my political career to a conclusion," Mr Minchin said.
"I will step down from the Shadow Ministry forthwith, and will vacate my Party's Senate leadership at a meeting of Liberal Senators...
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"I intend to serve out the rest of my Senate term until 30 June 2011 on the backbench," he announced on Wednesday.
Senator Minchin is one of the Coalition's longest-serving senators.
He has been in charge of the resources and energy portfolio since Tony Abbott became Opposition Leader.
But he is understood to have been considering his position since his son Oliver, 19, was seriously injured in a boating accident earlier this year.
Coalition reshuffle
"Recent events involving my immediate family have been a factor in my decision," Mr Minchin confirmed.
Oliver, a Defence cadet, was thrown from a boat on Lake Burrinjuck in NSW and then run over by the propeller.
Mr Minchin's departure could be seen as a huge blow to the Opposition, with Mr Abbott still reeling in the wake of yesterday's health debate.
But it could also be an opportunity for the Opposition Leader to reshuffle his front bench.
This may include dumping Barnaby Joyce from the finance portfolio and replacing him with Tony Smith, who is now serving as shadow communications minister.
On Wednesday, Mr Minchin reiterated his support for Mr Abbott, who he said had his full backing.
"I will be doing everything I can to help the Coalition return to Government at this year's Federal election under Tony Abbott's strong leadership," he said.
