Malcolm Turnbull has stepped down as communications minister to challenge Prime Minister Tony Abbott for the leadership of the Liberal Party.
At a brief Parliament House press conference this afternoon, Turnbull said he had asked the prime minister to facilitate a meeting of the Liberal party room to enable a leadership ballot.
"Now this is not a decision that anyone could take lightly," Turnbull said.
"I have consulted with many, many colleagues, many Australians, many of our supporters in every walk of life. This course of action has been urged on me by many people over a long period of time.
"It is clear enough that the government is not successful in providing the economic leadership that we need. It is not the fault of individual ministers. Ultimately, the prime minister has not been capable of providing the economic leadership our nation needs. He has not been capable of providing the economic confidence that business needs."
"The big economic changes that we're living through here and around the world offer enormous challenges and enormous opportunities and we need a different style of leadership," Turnbull said.
"We need a style of leadership that explains those challenges and opportunities, explains the challenges and how to seize the opportunities. A style of leadership that respects the people's intelligence, that explains these complex issues and then sets out the course of action we believe we should take and makes a case for it.
"We need advocacy, not slogans. We need to respect the intelligence of the Australian people."
If Abbott remains the prime minister, opposition leader Bill Shorten will succeed in unseating the government, Turnbull said.
"We have a hugely talented team here in the parliament," Turnbull said.
"Our values of free enterprise, of individual initiative, of freedom, this is what you need to be a successful agile economy in 2015. What we have not succeeded in doing is translating those values into the policies and the ideas that will excite the Australian people and encourage them to believe and understand that we have a vision for their future."