Malcolm Turnbull is a former Rhodes Scholar and self-made millionaire who had flourishing careers in law and banking.
A former head of Australia's republican movement, Mr Turnbull (60) first rose to international prominence in the mid-1980s as the brash young lawyer who represented Peter Wright, a former senior British intelligence operative with MI5, who took on the British government in the famous Spycatcher case.
Mr Turnbull succeeded in blocking British attempts to prevent publication of Wright's memoirs.
But the case was just the beginning of a long, prominent career which always seemed destined to be headed towards a tilt at becoming the nation's leader.
Polls show he is far more personally popular than Tony Abbott, pictured, and his leadership could potentially give the ruling coalition a much-needed boost. "We have to make a change for our country's sake, for the government's sake, for the party's sake," Mr Turnbull said.
A former party leader, Mr Turnbull was deposed by Mr Abbott in 2009 but few believed his ambitions could be contained in his role as communi-cations minister.
Mr Abbott (57) and Mr Turnbull, both Catholics, have long been rivals and the two have had strikingly similar careers.
Both attended private schools in Sydney, completed law degrees at Sydney University, studied at Oxford as Rhodes Scholars, and started their careers as journalists.
Mr Turnbull was a republican leader in the lead-up to the failed referendum on the issue in 1999; Mr Abbott was a leader of the monarchists. Both are married with children: Mr Turnbull has two, Mr Abbott has three.
Mr Abbott defeated Mr Turnbull as opposition leader by one vote in 2009 and went on to become prime minister, the job which the latter has always coveted.
Socially progressive and a strong supporter of gay marriage, Mr Turnbull has long had high public approval ratings but has been mistrusted by many in his party, particularly among the more conservative wing.
He was ousted in 2009 partly because of his call for action on climate change but has spent the past year trying to reach out to the party's conservatives and has already made clear that he will not swiftly move to legalise gay marriage. (© Daily Telegraph London)