Sam McMahon, who was part of the Country Liberal Party before resigning in January, used her valedictory speech to call out allegations of bullying within her former party.

"My losing preselection was not connected to my resignation at all. It was a democratic decision and they exercised their right to do that, I have no problem with that," the Northern Territory senator told parliament.

"My (decision) to resign was driven entirely by my former staff member Jason Riley who abused and terrorised my office - including myself - and the party's decision to place him into a position on their central council."

Senator McMahon says the actions of Mr Riley resulted in her needing professional help to address mental illnesses.

"To have to sit in meetings with such a person was stressful and one that has not been without me seeking out professional assistance to overcome the anxiety and post-traumatic stress disorder it created," she said.

She also reflected on her relationship with the late Labor senator Kimberley Kitching who was laid to rest last week following her sudden death at 52 from a suspected heart attack in Melbourne on March 10.

"I think of the premature death of my colleague Kimberley Kitching and one thing that haunts me is that could have been me," she said.

"We need to accept that poor behaviour is part of our profession and it's a part that needs to be eliminated from our game."

Senator McMahon says reports that Senator Kitching was bullied by her Labor colleagues should not become "a partisan football", as it is not constrained to any one side of politics.

"We will now find ourselves tempted to point to the other side with an attitude of 'look over there, see what they did'," she said.

"We should refrain because bullying, harassment and victim-blaming can still be occurring on all sides of politics.

"We can honour her memory by not making this a political issue but by fixing it so we can make politics a better place, particularly for women."

The outgoing senator also thanked her staff and National party colleagues, calling Deputy Prime Minister and Nationals leader Barnaby Joyce an "absolute rock".

Senator McMahon - a qualified veterinary surgeon - says she has not decided what she will do following her time in politics.

The 54-year-old was elected to the Senate in 2019 and lost a preselection battle with Alice Springs deputy mayor Jacinta Price in mid-2021.

She championed the right of the NT to vote on voluntary assisted dying, which it cannot legislate due to federal legislation overruling territory law in 1997, but her private senator's bill was never voted on.

Australian Associated Press