Roundup: Australia's "most successful" trade minister to leave Turnbull gov't

Australia's Trade Minister Andrew Robb, who orchestrated the ground-breaking free trade agreement with China, said on Thursday that he will be retiring from politics at this year's election.

Robb, 64, is the latest in a long line of coalition cabinet ministers who have either retired or been forced out of their position since it took power in 2013, but the outgoing Trade Minister told the Australian Broadcasting Corporation (ABC) that the "time was right" to call time on his own accord.

"I'm 64 and in excellent health, I feel I've got another career left in me," Robb said following his announcement.

"There are things I want to do, particularly in the private sector and some in the mental health space, and I didn't want to leave that too late," he said.

"After 12 fulfilling and eventful years (in politics) I feel the time is right."

Aside from being in charge of negotiating the China-Australia Free Trade Agreement (ChAFTA), Robb was also at the helm when Australia was negotiating trade pacts with other Asian powers Japan and Korea, and earlier this month he signed the Trans-Pacific Partnership, opening up further Australian export opportunities with the world.

Prime Minister Malcolm Turnbull reportedly asked Robb to reconsider his retirement after the premier was informed in December last year, but Robb said he would just see out his post until the federal election which is purportedly to be held in "August or September."

"(Turnbull) has said to me that he would like me to stay on for some time, some months, perhaps, so that I can try and complete a couple of important areas of business that I have got to a fairly advanced stage," Robb said.

The outgoing minister, who is currently in advanced talks with India, Singapore and Indonesia about signing potential agreements with them, told reporters in Canberra that he would be "doing my best to conclude" those before he calls it quits.

In a statement, Turnbull described Robb as the "most successful Trade Minister in Australia's history."

However, the news brought into light the mass changes the coalition government has undergone since it came into power in 2013, with twelve cabinet ministers either retiring or being fired from portfolio positins in under three years.

Aside from Robb, then-Prime Minister Tony Abbott was dethroned in September last year, while right-hand man and Treasurer Joe Hockey was also dumped in the reshuffle initiated by Turnbull when he took over.

Following them, former frontbenchers Eric Abetz, Kevin Andrews, Bob Baldwin, Bruce Bilson and Michael Ronaldson were all relieved of their positions in the cabinet reshuffle, while Mal Brough is currently under Australian Federal Police investigation.

Jamie Briggs was also stood down for inappropriate behavior while David Johnston and Ian Macfarlane were also dumped before they could complete a full term.

Adding to the chaos, Nationals leader and Infrastructure Minister Warren Truss is also expected to announce his retirement on Thursday.

Despite the unrest, the coalition has said the turnover of ministers will have a "positive effect" going forward.

"We're very lucky in the coalition that we have such a depth of talent," Indigenous Affairs Minister Nigel Scullion told the ABC.

"I think if anything it'll have a positive effect on government." Endit