Scott Morrison's first challenge as party leader during Question Time was to explain why he is Prime Minister.

Key points: Mr Shorten repeatedly asked why Australians have a new Prime Minister

Mr Shorten repeatedly asked why Australians have a new Prime Minister Mr Morrison defended his new role, saying "when placed in command — take charge"

Mr Morrison defended his new role, saying "when placed in command — take charge" Government ministers were questioned about their loyalty

"Malcolm Turnbull is no longer Prime Minister of Australia — why?" Labor leader Bill Shorten asked Monday.

The freshly minted PM turned to the words of a United States military leader to help him answer that question.

He quoted General Norman Schwarzkopf, saying "when placed in command — take charge".

"And that is what I propose to do Mr Speaker, take charge," Mr Morrison told Parliament.

It was not good enough for Mr Shorten, who followed up with another demand: "The Australian people deserve an answer — why did you change the prime minister?"

Mr Morrison's first Question Time was always going to see him face a pop quiz from the Opposition about the leadership turmoil he had termed a Muppet Show.

"The privilege of serving as the leader of the Liberal Party is a decision of the parliamentary party, and they have made their decision. I have accepted their decision," the PM said.

"And more than that, I have decided to take charge of that situation and deliver the strong economic growth.

"Keeping our economy strong, keeping Australians safe and keeping Australians together — that is my plan, and Australians will be backing it."

Again, that was not an acceptable answer for Mr Shorten.

"I asked not how the prime minister was replaced, but why," Mr Shorten again pressed.

Mr Morrison went further towards answering that, suggesting he was more likely to connect with people than his predecessor.

"The party chooses the person they want to lead to ensure that we can put the best foot forward at the next election, to ensure we are connecting with Australians all around the country," he said.

Labor has countered Mr Morrison's attempt to create an air of stability by pointing out the recent flood of leaks apparently aimed at damaging his Government.

"Is this what the Prime Minister meant when he said his own Government was a Muppet Show?" Deputy Opposition Leader Tanya Plibersek asked.

"As I said, the curtain is down on that performance," the PM said.

Loyalty was the dominant theme of the Labor interrogation.

After challenging Mr Morrison's legitimacy as Prime Minister, the Opposition turned to the ministers who were known to be supporters of Peter Dutton during the week of leadership turmoil.

Opposition health spokeswoman Catherine King targeted her counterpart, Health Minister Greg Hunt.

"Can the Minister confirm … he supported a Turnbull Government on Monday, voted for a Turnbull Government on Tuesday, said he supported a Dutton government on Wednesday, called for a Dutton government on Thursday, and pledged his loyalty to a Morrison Government on Friday?" Ms King asked.

"Can the Minister confirm when he told the House he supported Malcolm Turnbull, he had already decided to support someone else?"

Mr Hunt responded that Labor was not prepared to ask him about his portfolio.

"This is an Opposition that cannot even raise the will to ask a question about Health," Mr Hunt said.