Large companies and mining corporations could be paying more tax under a plan by the Greens that is reminiscent of a former Labor policy. 

Leader Adam Bandt said the measures would bring in $338 billion over the next decade, which would help fund dental appointments and mental health support, as well as lift the JobSeeker rate.

Elements of the policy mirror Labor's controversial mining tax that passed in 2012 but was later repealed by then-prime minister Tony Abbott. 

The Greens' Corporate Super-Profits Tax is the party's attempt to stake out some political ground ahead of the looming federal election, which is likely to be held next year.

However, there are a lot of pieces of the political puzzle that need to fall into place for it to become a reality.

Greens say higher tax is needed

Mr Bandt believes many Australians support big business being hit with additional costs. 

"While everyone else has suffered through the pandemic, billionaire corporations have made out like bandits and profits are at record highs," he said. 

"A 'tycoon tax' is essential because there's huge wealth in this country, but it's being hoarded by a greedy few."

Under the proposal, a company that has a turnover of more than $100 million would be slugged with the 40 per cent corporate super-profits tax. 

Loading

The new tax would apply to a company's net revenue, after income tax and a "fair return to shareholders" is deducted. 

Independent economist Saul Eslake explained how it could work. 

"In effect, they're saying that any company which generates profits that represent a return to shareholders in excess of 6 per cent, or thereabouts, after a payment of the normal company tax, should be paying an additional 40 per cent of those so-called excess profits to the government by way of tax," he said.

Mr Eslake argued that Australia's corporate tax rate was already higher than many other countries. 

"Among the 38 or so member countries of the OECD, only Portugal and Colombia, neither of which are particularly developed, have higher statutory corporate tax rates than Australia does," he said. 

"Indeed, Australia gets a larger proportion of its total tax revenue from company tax than most other so-called Western economies.

"So the case for Australia to do more in that context is, I think, not very compelling."

The tax bill issued to mining companies would be assessed on a project-by-project basis, which is what was recommended in the Ken Henry review commissioned by the former Labor government.

It led to the introduction of the mining tax in 2012 after years of negotiating and lobbying.

That tax was repealed two years later by the Coalition government.

However Mr Bandt is confident there is still support within opposition ranks to bring back such a tax. 

"I think the case for a super-profits tax on these billionaire corporations, in a style originally proposed by Kevin Rudd, is only going to grow," he said. 

Collecting billions to help millions 

The policy would raise $338 billion over a decade, according to costings by the parliamentary budget office. 

Mr Bandt said he wanted the money to be spent on affordable housing, lifting the JobSeeker rate and boosting Medicare funding.

"We should be firstly using this money to get dental fully into Medicare, mental health fully into Medicare, to help deal with some of the stresses of the pandemic," he said. 

"That is going to go a long way to relieving the pressures on everyday people and making life better for all of us. 

"And if the billionaires and big corporations have to pay their fair share and pay a bit more to do that, I think most people would agree with that." 

Taking from the past and looking to the future

The COVID-19 pandemic has all but sidelined opposition and minor parties, who have struggled to cut through in the past 18 months because they haven't been able to offer serious alternatives to what the government has provided. 

Today's announcement is the Greens' attempt to capture the public's attention and also put pressure on Labor to consider how it will fund essential services, like Medicare, into the future. 

"We are putting a very clear and bold plan on the table that will deliver for people," Mr Bandt said. 

But the delivery of the policy rests on several elements falling into place, including Labor winning minority government. 

Mr Bandt is hopeful the Greens will pick up additional seats in the Lower House, giving them more leverage in shaping the political narrative. 

"I'm optimistic that if the Greens get put into the balance of power at the next election, that ideas like these can become a reality," he said. 

The ABC's election analyst Antony Green said at this stage it did not look like Labor would need the Greens in the Lower House.

"At the moment the polls have swung quite strongly in favour of the Labor Party. They will win the election based on the most recent polls, but the most recent polls aren't going to be the result at the next election, there is a long time to go before people vote," he said. 

Numbers aside, while some within the ALP may think the policy is worth considering, it is unlikely the opposition would back such a proposal ahead of an election.

The Labor party is all too aware of the deep pockets of the mining and big business interests that could fund a campaign against the move.

In what is set to be a tight election race, Opposition Leader Anthony Albanese is unlikely to want to rock the boat.

However, the issue could be a tricky one for Labor candidates contesting seats where the Greens have a chance of winning.