Defence Minister Christopher Pyne has formally announced he’s quitting politics, becoming the second of Scott Morrison’s ministers in 24 hours to confirm they are retiring at the next election.

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 Pyne, who has held the seat of Sturt since 1993, confirmed his exit 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.

Speaking to reporters in Adelaide a short time later, Mr Pyne said he contemplated his future in politics while down at the beach in January.

“I’d like to thank my family and my staff for creating opportunities for me, to do what I have done for over a quarter of a century.

Mr Pyne said he’d look at job opportunities in the private sector and “try and create a business”.

“I had two years as a lawyer, some would say I was pretending to be a lawyer while campaigning to get into politics. I think there is some truth to that but I intend to go into the business world and see where that takes me.

“I thought about it over January and February. I went back to parliament for two weeks to get the party through those two weeks given we’re a minority government. I thought about it more carefully over the weekend, decided I wanted to leave and told the prime minister on Tuesday,” he said.

“Whether we win the election in May or whether we lose the election in May, I would be making the exact same decision,” he said, adding that he had “every confidence” the PM will lead his party to victory.

Defence Industry Minister Steve Ciobo also confirmed on Friday he will quit at the May election and “do something else”, preferring to stand down from his ministry immediately.

Mr Morrison is expected to elevate Linda Reynolds to cabinet as defence industry minister, media reports say.

“Linda has the talent, the experience, the knowledge and the determination to get the job done,” Mr Morrison said.

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.

“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.”

Federal politics ‘anti-family’

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.

-with AAP