Brough admits he feared embarrassing himself when entering politics

Retiring former Turnbull minister Mal Brough feared he would be an embarrassment when he first started in federal politics two decades ago.

He was worried he wouldn't be up to the mark because he wasn't a Rhodes scholar or a brilliant orator.

The Sunshine Coast MP delivered his valedictory speech to federal parliament on Thursday, reflecting on a long political career.

Mr Brough resigned from the Turnbull ministry in February, having earlier stood aside amid a police investigation into his alleged role in the Peter Slipper-James Ashby affair.

He was also a Howard government minister but lost his seat of Longman at the 2007 election, later replacing Mr Slipper in Fisher at the 2013 election.

"My journey started here 21 years ago and when I came to this place my greatest fear was that I'd be an embarrassment - I figured everyone in this joint would be a Rhodes scholar, a brilliant orator.

"I just wanted to make sure I didn't let the people of Longman down."

However, Mr Brough celebrated the fact that unlike his colleagues, he never spent a day in opposition.

"I knew when to leave and knew when to come back."

Mr Brough thanked former prime minister John Howard for giving him opportunities in the ministry.

His time as indigenous affairs minister would remain a big part of his life until the day he died.

He touched on the apparent suicide of a 10-year-old girl in a remote West Australian community earlier this month.

It would have garnered worldwide news if she had been white, he said.

"It didn't make our parliament and that is a refection on all of us.

"These are tragedies in our backyard and we collectively are responsible."