Speaking on TVNZ's Q&A this morning Mr Cunliffe said the "visionary policy" would see half of the remaining dividend flows from part state owned energy companies put into the fund and managed by the NZ Superannuation Fund "to invest in high growth New Zealand assets".
Mr Cunliffe said Labour would take "new revenues from the oil industry" either from new wells or through increased royalty levels.
A Labour review of oil and gas royalties would bring them up "to a fair level that doesn't exceed Australia's".
"This will mean New Zealanders get a fair share from their resources and provides more funds for NZ Inc Sovereign Wealth Fund."
The remaining stakes in the former state owned energy companies would be protected from future sell downs by deeming them to be 'KiwiShares' a more direct variation of the structure set up to protect public interests in Telecom when it was privatised in the early nineties.
Mr Cunliffe conceded there would be nothing to prevent a future Government selling down any stakes put into the KiwiShare structure, but that would be "a very public and politically difficult thing to do".
Speaking to party faithful at Panmure Bridge School this afternoon, Mr Cunliffe said the idea behind NZ Inc was that "we draw together our publicly owned resources and use them to build a publicly owned asset base that can drive long term sustainable growth", and create new high paying jobs.
Later, he told reporters the initial $100 million a year Labour would commit to the fund was enough to get it started.
"Obviously it's going to grow over time, partly because it would compound, partly because we're going to look to add to that with future revenues from both SOEs [state owned enterprises] and from the oil and gas industry"
Mr Cunliffe said it was important to understand Labour would not use the fund to buy back privatised assets like the half shares in power companies sold off by National.
"This is an economic growth fund not a state asset buy back fund," he said.
"This is a fund that will invest to create the maximum benefit for future New Zealand of strategic assets and clean technologies -- some of those might happen to be shares in previously privatised SOEs but many of them will be in young companies that have particular potential to drive value in the New Zealand economy."
National Party associate finance spokesman Steven Joyce said Labour's plan was "just another way of pre-committing money that has already been committed by Labour a few times over".
"Dividends received by the Government from state-owned enterprises are already being used to pay for public services like education and health and to pay down debt.
"They can't just keep being spent again and again. On top of that, the so-called 'strategic investment' language is quite obviously code for spending money on experimental cleantech investments that have lost money the world over."
