KEVIN RUDD has denounced the unfettered capitalism of the past three decades and called for a new era of "social capitalism" in which government intervention and regulation feature heavily.

In an essay to be published next week, the Prime Minister is scathing of the neo-liberals who began refashioning the market system in the 1970s, and ultimately brought about the global financial crisis.

"The time has come, off the back of the current crisis, to proclaim that the great neo-liberal experiment of the past 30 years has failed, that the emperor has no clothes," he writes of those who placed their faith in the corrective powers of the market.

"Neo-liberalism and the free-market fundamentalism it has produced has been revealed as little more than personal greed dressed up as an economic philosophy. And, ironically, it now falls to social democracy to prevent liberal capitalism from cannibalising itself."

Mr Rudd writes in The Monthly that just as Franklin Roosevelt rebuilt US capitalism after the Great Depression, modern-day "social democrats" such as himself and the US President, Barack Obama, must do the same again. But he argues that "minor tweakings of long-established orthodoxies will not do" and advocates a new system that reaches beyond the 70-year-old interventionist principles of John Maynard Keynes.