Outgoing ACT MP Brooke van Velden has defended her infamous Parliamentary c-bomb and called for the abolition of the Public Service Commission during her final speech in Parliament.

The party's former deputy - who is the MP for Tāmaki - is leaving politics at the November election.

She is also due to have her first baby early that month but, on announcing her pregnancy, said that was not the reason for her departure.

Van Velden said she was spurred into Parliament following her work with ACT leader David Seymour on the End of Life Choice Act before she was an MP.

"Working on that law will remain one of the greatest privileges of my life," she said on Tuesday. 

"It convinced me to dedicate the past few years to public service, to advance more laws that benefit New Zealanders."

Public office could be tough: "The abuse, the personal attacks and the concern for safety," van Velden said.

"While I can't control other people's actions, I can control how I respond... Those attacks have been met by turning the other cheek and getting on with the job."

However the clear exception, she said, "was the fateful day of the c-word".

Van Velden used the word in Parliament last year in protest over the slur being directed at her and other female ministers in a newspaper column.

"I'm proud to have stood up to that misogyny - for my colleagues and for every woman who stays silent out of fear of being labelled the wrong kind of woman.”

Van Velden also called for the Public Service Commission to be abolished, saying it did not work for the public or governments.

"It works for the public service to preserve the status quo, enable public servants to shuffle between agencies while leaving the failures of their roles behind with no accountability or meaningful consequences.”

Instead, ministers should hire chief executives directly, van Velden believed.

"If that were the structure, I believe we'd see better accountability and transparency over decision making, and over where the money goes."

Van Velden said the various causes she advocated for - including fundraising for the Ukrainian effort and allowing pregnant women to re-enter their own country under Covid-19 restrictions - were underpinned by her belief in freedom, choice and democratic rights.

She said she left proud of her work repealing and replacing the Holidays Act and improving government efficiency.