Keenan confident Libs will keep his seat

Human Services Minister Michael Keenan has no doubt his Perth seat of Stirling will remain in the hands of the Liberal Party when he stands down at the next election.

"I am very, very confident that we will retain the seat," Mr Keenan told reporters in Perth on Saturday.

Mr Keenan on Friday evening revealed his intention to leave federal politics after 15 years, to spend more time with his family.

After "agonising" over his decision he said he wanted to prioritise time with his wife, Georgina, and their four children, all under the age of seven.

But he's determined to ensure his replacement gets elected and knows a couple of women who would be perfect for the job.

"We'll have a pretty strong field. I do know of a couple of very good women and I'm hoping that they'll put their names forward," he said.

Mr Keenan is the third government minister in a week to announce he won't be running again at the federal poll.

Jobs Minister Kelly O'Dwyer last week revealed her intentions to bow out, as she aims to have a third child and spend more time with her first two.

Indigenous Affairs Minister Nigel Scullion on Saturday announced his plans not to run for his Senate seat again.

But there's nothing unusual about such a series of departures, Mr Keenan says.

"I don't think it's particularly striking that there are several ministers deciding after Christmas, and at this time of the year with an election looming, that they can't serve for the next three years," he said.

Before taking on the human services and digital transformation portfolios in late 2017, Mr Keen was minister for justice for five years, assisting the prime minister with counter-terrorism for the last two.

That came at a time when the security situation in Australia was deteriorating, he said.

"I was part of a government effort that was very, very successful in arming our agencies to make sure that Australia was free of the sort of terror attacks, or largely free of the sort of terror attacks we saw in many of our friends and allies overseas."

Prime Minister Scott Morrison said he had worked with Mr Keenan for a long time, including in border protection while in opposition.

"The work he's done to keep Australians safe, I commend him for, and he's been a great member of the team," he told reporters after a citizenship in Canberra on Saturday.

The outgoing minister has been equally complimentary to his leader.

"I'm sorry to be leaving the team but I have great faith and confidence in that team. The prime minister is doing a fantastic job," Mr Keenan said.