Mr Goff launched his attack on Mr Key's record at a conference of the Rail and Maritime Transport Union in Porirua.
He said his attack was not about John Key personally. But he went on to say: "I think it's hard to be smug about these facts and figures.
"I know what excuses John Key will use when he's confronted with these figures because he's really good at describing the problem but not so good at fixing it."
Mr Goff said the Canterbury earthquakes had simply made a really bad situation worse. New Zealand had weathered the storm only because of the actions of the last Labour Government.
Mr Key's record was to cut taxes for the rich, and borrow to pay for them, put up GST and hack twice at KiwiSaver.
Mr Key's plan to get New Zealand out of the mess if he won a second term was asset sales.
Mr Goff received a standing ovation when he talked about keeping Orion energy in Christchurch in local hands.
Mr Key said from Christchurch that Mr Goff was often criticising him for the $18 billion deficit - a New Zealand record "half of which relates to Christchurch, half of which relates to spending money to do the very things he also wants to criticise me about and claim I'm not protecting vulnerable New Zealanders when I have been.
"If we'd walked away from Working for Families, abandoned benefit entitlements, been incredibly tough on people, not insulated homes, not made sure they had access to free health care and the like, I think you could ... criticise us for abandoning people."
But with all the things the Government had had to contend with, he thought the balance was "about right".
Goff's Top Ten list of Government failings
1. Unemployment has increased by 50 per cent, leaving 157,000 New Zealanders out of work.
National rebuttal:
Employment has risen over 60,000 in the last two years. Most of the unemployment growth occurred prior to Budget 2009, as a result of the global economic recession and New Zealand's own recession which commenced at the start of 2008 and pre-dated the change of Government.
2. 100,000 New Zealanders have left for Australia after he promised he would stop the brain drain.
National's rebuttal:
Almost 300,000 New Zealanders left during Labour's time in office, which underlines that the number of Kiwis leaving for Australia has been a problem for many years. New Zealand's competitiveness with Australia has declined over decades. National has been clear that is going to take time to turn it around, and is focused on improving New Zealand's international competitiveness to achieve that.
3. Prices have gone up nearly four times faster than incomes over the past three years. Key raised prices by hiking GST after promising not to.
National's rebuttal:
After-tax wages have, in fact, risen by 10 per cent over the last three years, after allowing for inflation.
4. The first credit rating downgrade in 13 years and a double downgrade at that.
National's rebuttal:
The downgrade by two of the three ratings agencies is largely a result of increasing international aversion to debt. In New Zealand's case the doubling of private sector debt over the nine years of the Labour government is the biggest single issue with our international credit rating. That is why it is crucially important to not add too much debt over the next four years. Labour wants to increase debt by $15.6 Billion more over that period.
5. There are 60,000 more people on benefits costing an extra $1 billion a year.
National's rebuttal:
The number of people on benefits rose as a result of the recession that began in early 2008. However since January 2010, the number of people reliant on benefits has dropped by 20,000 and continues to fall. National's welfare reforms and our focus on jobs are targeted to reduce benefit numbers by over 40,000 over the next four years.
6. The wage gap with Australia has increased by $32 a week.
National's rebuttal:
The after-tax average wage in New Zealand has, in fact, grown faster than in Australia over the last three years.
7. There are 55,200 15 to 24 year olds not in education, employment or training.
National's rebuttal:
This is an issue that was been around for many years. Eight years ago Labour promised that all 15-19 year olds would be in education, training or work by 2007. National is using trades academies, Youth Guarantee, National Standards in schools, and other programmes to tackle this issue.
8. The economy has grown by just 0.4 per cent since John Key took office.
National's rebuttal:
Labour's legacy was that the economy shrank by 3.4% in the year before National's first budget. Since National's first budget in 2009, the economy has grown in eight of the last nine quarters.
9. National's tax cuts for the wealthy were to be paid for with GST. They actually cost an extra $1.1B in their first nine months.
National's rebuttal:
The 2010 tax package means that around three quarters of taxpayers now pay an income tax rate no higher than 17.5%. The tax package is fiscally neutral over four years. We are one year into that package.
10. The underclass has grown with the number of kids in benefit dependent households increasing by over 32,000 in the past three years.
National's rebuttal:
The New Zealand recession followed by the world economic recession has increased numbers of New Zealanders on benefits. We have protected the vulnerable over the last three years by indexing their incomes against the cost of living. National's jobs and growth plan will reduce the number of benefit-dependent households as the economy recovers.
