Labour leader Andrew Little has called for an immediate cut in ACC levies, saying the corporation was set to collect $350 million a year more than needed.
Mr Little said the money should be left in the hands of workers and businesses.
The figures comes from a report by Infometrics into the economic impact of the new 2015-2016 rates, which come into effect on April 1.
It found cutting rates lower than approved by the government could boost the economy by $70 million a year, and stimulate a net increase of 590 full-time equivalent jobs, or up to 700 net new jobs.
"Government is using ACC as a cash cow by taking $350 million dollars more than needed out of the pockets of businesses and workers," Mr Little said.
"The report shows that costs 700 jobs. It's tough for Kiwis to get secure, well-paid work. As a country we need those jobs each year."
Mr Little told Newstalk ZB this morning that ACC had significant reserves, and was well placed to cut levies.
"Is ACC collecting enough or more than they need to fulfil their statutory obligations? The answer is yes. And it's not just by a small margin, it's by a significant margin, $350 million a year."
"So what we're saying is cut the levies, to suit. They're in a good state financially, reserves of over $30 billion, and the two main accounts, workers account and earners account, are oversubscribed by more than a third."
Levies are paid by employers and employees to cover the cost of workplace injuries, and other injuries suffered by workers.
In 2014, the government rejected a recommendation from ACC that levies for the 2015/16 year be cut by 21 per cent for the work levy on employers, and by 5 per cent for the earners' levy on workers.
Instead the work levy was cut by 5 per cent, and the earners' levy remained the same.
ACC Minister Nikki Kaye said on Facebook yesterday that Mr Little's data was old and he had failed to learn from Labour's past.
She said the previous Labour government left a $5 billion hole in ACC.
"This was caused by a range of things but what was clear is they expanded entitlements without understanding costs and they didn't understand the wider economic issues and the effects of things like discount rates. These fluctuations can be large.
"We have announced levy reductions of $1.5 billion and I am sure there will be more to come as we confirmed in our 2014 election policy.
"However, what is needed is a long term funding policy and framework that can withstand these shocks. That will give certainty for businesses so levies aren't constantly shifting up and down."
Ms Kaye said there would be more reductions in levies in the future.
"We make no apologies for being slightly more fiscally conservative over the last few years, but I'm confident there will be further levy reductions."
She said it was a question of timing and planning long-term.
"These accounts do bounce around quite a bit."
She said she would be looking at whether levy reductions could be made, while looking at long-term projections of the accounts to minimise risk.
"We need to ensure businesses have certainty and stability," she said.