Opposition Senate leader Simon Birmingham to retire from politics

Coalition Senate leader Simon Birmingham has announced his retirement from politics.

The South Australian Senator, 50, will step down after the next election.

Birmingham told his colleagues outside the Senate chamber today in Parliament House.

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He then made a valedictory speech in the Senate and thanked his Liberal colleagues.

The Senator said it was "time for my parliamentary service to pass".

"Now is the right time for me, for my family and for new career pathways," he said.

"I am excited that next year I will step into a new commercially-oriented direction."

Birmingham joked his new role would have "nothing to do with lobbying, government relations or commentary".

"Professionally I will leave here just short of 18 years serving the great state of South Australia," he added.

"I've seen, during those near 18 years, too many prime ministers and acknowledged the political blood on my own hands during those more turbulent times."

He then thanked several Liberal prime ministers he has served under, particularly John Howard, Malcolm Turnbull and Scott Morrison.

The Senator serves as both the Liberal leader in the Senate and shadow foreign minister.

He began his career in politics in 2007.

Michaelia Cash will replace Birmingham as opposition leader and Anne Rushton is set to step up as deputy.

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Opposition leader Peter Dutton confirmed Birmingham's retirement in a statement in the lower house.

"Can I say thank you very much to Simon Birmingham, who has just announced his retirement as our leader of the opposition in the Senate," Dutton said.

"Birmo has a young family, and I know he's going to look forward to spending more time with them and and he's given an enormous amount to our country."

Prime Minister Anthony Albanese also acknowledged Birmingham's decision and described him as a person of "integrity".

"It is understandable he has made this decision but I wish him all the very best," Albanese said.