Government Senate leader Mathias Cormann is internally regarded as a reliable pair of hands, and some colleagues are breathing a sigh of relief he will be taking the federal reins next week as acting prime minister when Malcolm Turnbull is out of the country.

The Deputy Prime Minister and Nationals leader would normally be automatically elevated to the role, but Barnaby Joyce will be taking leave as he deals with the continuing fallout and questions about his affair with former staffer Vikki Campion.

It is curious the Prime Minister has chosen Senator Cormann to the acting position, given deputy Liberal leader Julie Bishop publicly indicated on Wednesday she would return from overseas to assume the job if needed.

“I am returning to Australia from Kuwait and I do have plans to be overseas next week, Parliament is not sitting. If circumstances change then of course, I would change plans,” she said.

So who is Mathias Cormann?

Senator Cormann was born in Belgium, also a constitutional monarchy, and migrated to Australia after finishing his studies.

He acknowledged his trademark “slight accent” in his maiden speech, and has sometimes played on his likeness to Arnold Schwarzenegger by quoting the famous “I’ll be back” catchphrase from the popular movie Terminator.

At 47 years of age, Senator Cormann has progressed to the senior ranks of the federal government.

The West Australian representative is already loaded with parliamentary duties, as Finance Minister, Senate leader and more recently Special Minister of State — a role he took after his Liberal colleague, Scott Ryan, took over as Senate President.

In those roles, Senator Cormann is helping prepare the May budget, has responsibility for overseeing parliamentary entitlements and is in charge of the running of the government’s Senate agenda.

He is also often heavily involved in negotiations on legislation in the Upper House.

Mathias Cormann is the Government’s leader in the Senate. Photo: ABC

But he’s no economic ‘girlie-man’

The trademark serious tone he takes dead-batting questions from reporters has been pilloried on the ABC program Mad as Hell, with a regular skit featuring an impersonator under the character name Darius Horsham.

Horsham has made regular use of Senator Cormann’s infamous criticism of Bill Shorten, when the Finance Minister called the Opposition Leader an “economic girlie man”.

Senator Cormann borrowed the phrase from the former California governor, Schwarzenegger, but he received widespread criticism at the time.

Labor’s rejection of budget measures in the Upper House has frustrated Senator Cormann over a number of years, leading him to make another famous criticism of Mr Shorten in 2016 in a prepared speech.

“Will Bill Shorten step up to the plate on budget repair in this Parliament, or will he continue to be like a jelly on that plate?” he said.

“Wibble wobble, wibble wobble jelly on a plate. First opposing, then supporting then not knowing what to do.”

Late last year, the senator made headlines after he took to the stage with an idol of his teenage years, German performer Nena, for a rendition of the pop song 99 Luftballoons.

It was a rare snapshot of the buttoned-up senator letting his hair down at a function related to the Asia-Pacific Regional Conference.

Senator Cormann outlined his political ambitions in his first speech to Parliament.

“An effective federal system of government helps ensure that governments remain close to the people,” he said.

“It encourages the decentralised development of our very large country, allowing for unique and innovative ways for tackling social, economic and political challenges and it provides for important checks and balances on government power.”

.@MathiasCormann – Minister for Cool. #Nena #auspol pic.twitter.com/Kc9xTar4RT

— David Speers (@David_Speers) November 4, 2017

He is a man of few slip-ups, but did fumble an interview during the 2016 federal election campaign, while he was the Canberra-based official campaign spokesman.

“Bill Shorten is very caring and very much in touch and Bill Shorten every single day is promoting our national economic plan for jobs and growth, which of course is exactly what Australia needs given the continued global economic headwinds,” he said.

He meant Prime Minister Malcolm Turnbull.

Ultimately technology means the real Prime Minister is not incommunicado any more like he was in the days when travelling overseas involved two weeks on a Cunard liner.

But it’s still an important role in terms of dealing with domestic issues while the Prime Minister is fielding mostly questions on international diplomacy.

-ABC