While Mr Goff was attacking Mr Key, Mr Key was in Christchurch announcing a $20 million temporary stadium with seating for 17,000 would be built in Christchurch for major sporting and cultural events.
The temporary stadium would host Crusaders and Canterbury ITM Cup home games as well as Phoenix football matches and rugby league games.
The All Blacks would play Ireland in the new venue in June next year.
Speaking at the Rail, Maritime and Transport Union annual conference, Mr Goff said there were many New Zealanders who voted for Mr Key rather than National in 2008. They continued to support him personally rather than National because they believed he had made a personal fortune for himself and maybe he could do that for New Zealand.
"But a look at his record shows that his success in business has not transferred to running the country and that he has failed to deliver for us."
As Mr Goff and Labour continue to trail Mr Key and National in the polls, it was only a matter of time before the Labour leader, who said the election was about policies not personalities, decided to turn the heat up on the Prime Minister. But even then he could not bring himself to be really nasty.
"This isn't about John Key the person. I'm sure he has the best intentions for New Zealand. It's about his record."
Every prime minister should be judged on their performance in such critical areas rather than hide behind a series of excuses, he said.
Labour campaign spokesman Grant Robertson joined in the attack of Mr Key.
Mr Goff released a list: On John Key's Watch - the top 10 you won't hear him read on Letterman. The list included: unemployment increasing by 50%, leaving 157,000 New Zealanders out of work; 100,000 New Zealanders leaving for Australia after Mr Key promised he would stop the brain drain; prices having gone up nearly four times faster than incomes over the past three years and Mr Key hiking GST after promising not to; the first credit rating downgrade in 13 years; the wage gap with Australia increasing by $32 a week; National's tax cuts were supposed to be paid for with the GST increase but had cost an extra $1.1 billion in their first nine months.
Many people voted for Mr Key on the basis of his promise of a brighter future and his claim he was ambitious for New Zealand.
"But the simple fact is he has failed to deliver. I think it's hard to be smug about these facts and figures," Mr Goff said in a veiled criticism of Mr Key's tendency to smile through almost any political circumstance.
"When you look at what he has actually done, he has cut taxes for the rich and borrowed to pay for them, put up GST and hacked twice at KiwiSaver.
"So there is his record. It's a record of underachievement and New Zealanders have paid the price with job losses, higher prices, lower wages and the prospect of further pain before it gets better."
The plan had for getting New Zealand out of the "mess" came down to two words, Mr Goff said.
And they were "asset sales".
Mr Key's whole economic plan was to sell things New Zealanders already owned to foreign banks.
"John Key's plan is for now. A short-term solution to a long-term problem. It fails to deal with the problems looming for our children and grandchildren. It just won't work." Mr Goff said his plan was simple, real and it would work.
Labour would keep the assets.
