Finance Minister Mathias Cormann has painted a doomsday scenario of Australia under a Bill Shorten government, claiming a "cocky" Labor leader is relying on the politics of envy to propel him to the Lodge as people forget the failures of socialism.

In an extraordinary speech designed to reset the political debate over fairness and economic management, and tackle head on Mr Shorten's prescriptions for how to fight inequality, Senator Cormann argued the Opposition Leader had trashed the Hawke-Keating legacy and abandoned economic reform.

The dramatic picture, delivered in a speech to the Sydney Institute on Wednesday evening, is arguably the most trenchant criticism yet of Mr Shorten's economic program and comes from one of the most senior and respected members of the Turnbull government.

The Opposition Leader is riding high in the opinion polls and has made a series of bold policy announcements, such as a crackdown on trusts to reduce taxable income and a promise for an initial referendum on whether to become a republic in his first term.