Christopher Pyne, Australia's Minister for Defence, and Steven Ciobo, the Minister for Defence Industries, on Saturday announced they would not contest May's election, with the latter stepping down as a minister immediately.

It is a challenge for Prime Minister (PM) Scott Morrison and the governing Liberal-National Party Coalition (LNP) having already been rocked by the announced departures of Jobs Minister Kelly O'Dwyer, Human Services Minister Michael Keenan, Indigenous Affairs Minister Nigel Scullion and former Foreign Minister Julie Bishop.

Pyne has served as the Member of Parliament (MP) for Sturt in South Australia since 1993 and as a Minister under three LNP PMs since the party won power in 2013.
Along with Bishop he was one of the party's leading moderates and a strong supporter of former PM Malcolm Turnbull who was deposed as leader in August 2018, paving the way for Scott Morrison to be installed as his successor.

"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," he said in a statement on Saturday.

"Twenty seven years ago I was preselected as the Liberal candidate on a platform of renewal in 2019, it is time to renew again.

"At fifty one, I still have the opportunity to have a second career beyond politics."
In a statement sent to reporters, Simon Birmingham, Minister for Trade, Tourism and Investment who is also from South Australia, said that Pyne "will retire from the Australian Parliament as the longest-serving South Australian non-Labor member in history."

"Christopher is renowned for his sharp wit, amazing sense of humour, and incredible verve. He can disarm a tense situation with a wicked observation, while maintaining a laser like focus on securing the desired outcome. He is indefatigable when under attack but has always believed that attack is the best form of defence," said Birmingham.

Ciobo was elected as the MP for Moncrieff in Queensland in 2001 and was sworn-in as a Minister when Turnbull replaced Tony Abbott as PM in 2015.

He ran for the deputy leadership of the Liberal Party after Turnbull's downfall but was defeated in a ballot by Treasurer Josh Frydenberg.

In addition to announcing his retirement from politics in May, Ciobo also stood down as the Minister for Defence Industries effective immediately, a decision he said he informed Morrison of weeks ago, with Senator Linda Reynolds to take his place in the lead-up to the election.

"This will ensure a consistency in our approach and the opportunity for a seamless handover to minister Reynolds, should we be successful at the election," Morrison said in a statement.

"As a cabinet minister in the defence portfolio minister Reynolds will also have a unique opportunity to transfer into the role in the event the government is re-elected."

The retirements come at a time when the government is trying to present a united front having been plagued by August's leadership crisis.
According to opinion polls the Opposition Australian Labor Party (ALP) is on track for a possible win at the election, which will be held in May.
However, both Pyne and Ciobo said that they were confident the LNP would be re-elected.

Bill Shorten, leader of the ALP, said that the series of high-profile resignations represented a loss of faith in the government.

"The Morrison government is divided, it's unstable and now we see people just simply giving up on the government," he told reporters on Saturday.

"I say to Australians, if the ministers in the government are giving up on the government then you should too. Labor, by contrast, is united and stable." 

Image: Christopher Pyne Twitter page