Veteran Liberal senator retires to seek 'new direction'

However, he ruled out lobbying, government relations or commentary.

Referencing an ancient Persian proverb, the South Australian said "now it is time for my parliamentary service to also pass".

"Some will be kind enough to be disappointed to see me go ... but some,  to them, I am sorry, especially for those who feel that I'm letting them or the team down at this time.

"It is always better to go when there are some wishing you to stay, and none of us is irreplaceable. 

"It is always better to go when there are some wishing you to stay" Simon Birmingham told senators. (Lukas Coch/AAP PHOTOS)

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

Senator Birmingham entered parliament in 2007 and has served as trade, finance and education ministers in coalition governments under Malcolm Turnbull and Scott Morrison.

The leader of the Liberal moderates faction is respected across the parliament and is seen as a loss to the party.

The 50-year-old backed the Morrison government's handling of the COVID-19 pandemic, and took aim at China's "abuse of power" when it slapped punitive trade restrictions worth $20 billion on Australian products.

"Australians should be proud that our businesses, our economy and our nation withstood that attempted coercion," Senator Birmingham said.

He rejected "perceptions" peddled by some in parliament that it was a universally toxic workplace. 

"Whilst we should never tolerate the type of behaviours that led to the Jenkins report, the whole should not have their experiences universally besmirched," he said.

The senator said little was gained by culture wars that risked social cohesion.

Labor Senate leader Penny Wong congratulated Simon Birmingham's on his "contribution to the nation". (Mick Tsikas/AAP PHOTOS)

"The global rise of populism and divisive tribalism peddled by ideological extremes troubles me," he said.

Thanking his wife and children, Senator Birmingham fought back tears as his family watched on from the public gallery.

"Those of you who have the honour of continuing in this place carry a great responsibility. 

"I wish you well, do good, make a positive difference. Thank you and farewell."

He received a standing ovation and Foreign Minister Penny Wong leaned over to shake his hand.

She saluted Senator Birmingham's career as a "great contribution to the nation".

"I congratulate Senator Birmingham on his service in this place. I thank him for his friendship, and I wish him all the very best for what's next."

Michaelia Cash praised Simon Birmingham's collegiate attitude, intelligence and negotiating ability. (Mick Tsikas/AAP PHOTOS)

Deputy coalition Senate leader Michaelia Cash said her colleague had won the respect of everyone in parliament.

"Your collegiate attitude, intelligence and the ability to negotiate successful outcomes, both within our team and within this place has, quite frankly, been second to none," she said.

Opposition Leader Peter Dutton thanked Senator Birmingham at the end of Question Time.

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

Prime Minister Anthony Albanese said the Liberal senator had "very broad respect right across the parliament, and he certainly has my personal respect".

"He's someone who is someone of integrity, who is easy to deal with and to get things done. 

"So to Simon and Courtney and their family, it is understandable that he's made this decision, but I wish him all the very best," he said.