He claimed the party was ignoring short term political expediency to make a "courageous decision about a better tomorrow".
"It's time to make a decision that will build a stronger future for New Zealand. We've got the balls to do that. John Key doesn't."
He followed that with a tweet claiming Prime Minister John Key did not have the "guts" to debate him.
"Key doesn't have the guts to debate the issues that matter to kiwis. He's only interested in the short term. I will make the tough decisions."
Meanwhile, Mr Key dismissed Labour's superannuation plans as a "cruel joke".
He said they meant more borrowing, more spending, more taxation and more costs on business, while forcing New Zealanders to work an extra two years.
"I guess when you saw them put up those billboards telling you they were going to take GST off bananas you never thought you'd have to work two years longer to pay for it, but that's what's come out today and, sadly, they are out of touch with what's required."
Mr Key said National's plan was balanced and would see the Government's books back to surplus within three years.
"We won't be putting big spending costs on the economy, we won't be taxing businesses more and you will be able to retire at 65 knowing that your pension is there."
Under Labour, "New Zealanders will lose their jobs, businesses will go to the wall and that's because Labour hasn't learned anything in the last decade, they just want to keep spending your money and now you have to work two years longer to pay for it," said Mr Key.
