He noted this morning that raising the entitlement age was one of a number of cost saving measures recommended by Treasury including getting rid of interest free student loans and ending Working for Families, neither of which he intended to do either.
But following his address to the conference, Labour leader Phil Goff said the prime minister was dodging the issue.
"New Zealanders in their hearts know the increase in the number of New Zealanders in retirement from half a million to 1.3 million, the cost is going to double."
By choosing not to deal with the issue while he was prime minister, Mr Key was allowing the problem to get much worse, "and leaving it for someone else to fix".
Meanwhile, in his speech, Mr Key said his Government had inherited Crown accounts in 2008 that were already showing the effects of recession even before the global financial crisis.
His Government had also dealt with the losses from finance company failures, and the Canterbury earthquakes.
"Difficult times are when sound, stable, and responsible government matters more than ever. Faced with challenges, the National-led Government set about dealing with them in a measured and balanced way."
Labour, on the other hand was offering "a collection of election gimmicks and slogans, which would create a $16 billion hole in the government's accounts.
Furthermore, Labour planned to load more costs onto businesses including an increase in the minimum wage, higher employer contributions to KiwiSaver, its plan for a capital gains tax, and an irrigation tax on farmers.
Speaking further on his Government's plan to put the proceeds of the partial asset sale plan into a fund which would be used to infrastructure investment, Mr Key again said further investment in KiwiBank was being considered.
Mr Key and Mr Goff's addresses were to be followed by presentations from the minor parties. Finance Minister Bill English and Labour finance spokesman David Cunliffe, the Greens' Russel Norman and Act's Don Brash were to outline their parties' approach to the economy this afternoon.