New Australian Prime Minister Malcolm Turnbull defended his major cabinet shake-up and said if the percentage of women in parliament had been higher he could have appointed more to key roles.

One week after deposing Tony Abbott in a swift, internal Liberal Party coup, Turnbull on Monday pleaded the case for renewal in his first television interview as leader after clearing out a raft of senior conservatives and appointing many of his own moderate supporters.

He upped the number of women in cabinet from two to five in a move seen as a significant change in style and tone for the unpopular government, with Marise Payne notably becoming the country's first female defence minister.

The New South Wales senator had held the low profile post of human services minister.

"Leaders have to make sure that there is renewal," Turnbull told Channel Nine.

"And that's why you have seen so many new faces in the cabinet, so many more women, so many more younger people."

Turnbull said he thought having two women cabinet ministers out of 19, as Abbott did, was "not enough".

"It would be good if it were more but as you know the percentage of women in the parliament itself is not as high as it should be," he said.

Turnbull on Sunday removed treasurer Joe Hockey, defence minister Kevin Andrews, employment minister Eric Abetz, industry minister Ian Macfarlane and popular small business minister Bruce Bilson.

Scott Morrison replaced Hockey, who is tipped to be named ambassador to Washington, despite voting for Abbott in Monday night's Liberal leadership vote that Turnbull won 54-44.

Julie Bishop remained as foreign minister and Sussan Ley as health and sports minister.

Kelly O'Dwyer was singled out by Turnbull as one of the new generation "with enormous capacity", who joins cabinet as small business minister and assistant treasurer. Michaelia Cash was appointed minister for women and for employment.

- Warning against 'novice mistakes' -

The new prime minister, whose arrival has brought a bounce in the polls, said leaders had to show "inspiration to be more innovative, more optimistic, more creative, more productive".

With commentators warning that the sacking of leading conservatives could ignite party feuding, Turnbull told ABC radio: "No-one could suggest that this cabinet, this ministry has been assembled on any basis other than merit."

He continued: "It is vital to have a contemporary, 21st-century government and that requires renewal."

Turnbull, a Republican who has campaigned for Australia to cut ties with the British monarchy, told Channel Nine it would not be worth raising the issue again until after the reign of Queen Elizabeth II.

"The priorities of the government and the priorities of most Australians are much more immediate and they relate to economic growth and jobs," he said.

"My own view ... is that the next occasion for the republic referendum to come up is going to be after the end of the Queen's reign."

Governor-General Peter Cosgrove swore in the new ministers at the capital Canberra.

The shake-up has been welcomed in mainstream media, with The Australian noting it "is transformative, remaking the federal government at the stroke of a pen in a signature intended to 'embrace' the future".

But there were also warnings the "potential for novice mistakes is high" and of "palpable" dissent among some of those dispatched to the backbenches.
Source: AFP