Two of Scott Morrison's ministers will retire from parliament at the election, leaving his frontbench further depleted just weeks out from the federal poll.
Two of Scott Morrison's ministers will retire from parliament at the May election, with Christopher Pyne formally announcing his decision on Saturday.
The Defence Minister confirmed his retirement after 26 years in parliament in a statement on Saturday morning.
"It's time to retire while people are asking me to stay, rather than continue and end up later with people telling me to go," Mr Pyne said.
"I'm confident that I leave my seat in good shape. I'm sure the Liberal Party will retain Sturt at the coming election.
"I have every confidence that the Prime Minister will lead the Coalition to victory when the election is held in May."
Speaking at a press conference on Saturday morning, Mr Morrison said he was not worried about the run of departures of his party members.
"The election is about what we are going to do and what we have done," he said.
"The personalities will change from time to time. But it is what you are doing that matters and what you are going to do that matters."
Defence Industry Minister Steve Ciobo confirmed on Friday he will quit at the May election and "do something else", preferring to stand down from his ministry immediately.
Mr Morrison has since sworn in Linda Reynolds to cabinet as defence industry minister.
"Linda has the talent, the experience, the knowledge and the determination to get the job done," Mr Morrison said.
Speaking about the appointment, Ms Reynolds said the role would be focused on not only the military but "emergency management and Queensland reconstruction".
"It is about ensuring that 80,000 men and women who serve our country in uniform have the best possible equipment that we can provide them," she said.
"Secondly, it is about ensuring that we used as much as possible of Australian industry resources in supporting our own men and women."
Another senior Liberal, Craig Laundy, is also said to be preparing to quit politics. The former small business minister holds the marginal Sydney seat of Reid.
Mr Pyne has held his South Australian seat since 1993.
"As Minister for Defence and before that Defence Industry, I've been responsible for delivering the $200 billion build-up of Australia's military capability, the largest in Australia's peacetime history," he said.
"I'm also grateful that the youth mental health initiative I created in 2006 called 'headspace' survived the Labor Government and has gone on to thrive and become a fixture in the mental health sector."
The prime minister has already lost frontbenchers Kelly O'Dwyer, Michael Keenan and Nigel Scullion, who will retire from parliament at the May poll.
Former foreign minister Julie Bishop, who turned down a role in Mr Morrison's cabinet, will also retire in May.
Mr Morrison will consider whether to reshuffle his ministry ahead of the election or have Mr Pyne take over Mr Ciobo's portfolio until May.
Mr Ciobo told The Australian he was proud to have worked on the Trans-Pacific Partnership and the Indonesian free trade deal when he was trade minister.
"After 17 years in parliament, I have taken the decision that it's time to move on to something else," he said.
Mr Ciobo left his retirement announcement late in part to ensure an independent candidate wouldn't have time to mount a challenge in his safe Gold Coast seat of Moncrieff.
He wanted a woman to replace him in federal parliament.
"I would love for it to be a women, I think there are some terrific women around who are interested in running for the seat," Mr Ciobo told Sky News in an interview aired on Saturday morning.
As trade minister for several years Mr Ciobo said he was on the road for 47 weeks a year.
"Federal politics is anti family, full stop. Don't let anyone ever pretend otherwise," he said.