If the Liberal Party were serious about revenue, they'd stop the free-ride for their big business mates in five easy steps --

1. Make multinationals open up the books

Because you can't tax what you can't see.

2. Actually resource the Tax Office properly, so they can do their jobs

Details of BHP's tax arrangements have been revealed in answers provided to the Senate Inquiry on corporate tax avoidance, initiated by Greens Leader Christine Milne.

"It's shocking but not surprising that BHP is paying next to zero tax on billions worth of profits," said Senator Milne.

"No one believes this kind of behaviour is limited to BHP. The big corporates are ripping us off and successive Liberal and Labor governments have let them get away with it.

The Greens have released a discussion paper of policies to crack down on tax avoidance by multinational corporations, which is costing our federal budget billions.

"We cannot tax what we cannot see. Both the public and the parliament have a right to know which companies are dodging their taxes," said Greens Leader Christine Milne.

"Joe Hockey is all talk about international cooperation some time in the future, but the Australian community can't afford to wait. Another Hockey budget is only three weeks away.

At the conclusion of three days of hearings in the Senate corporate tax avoidance inquiry, Greens Leader Christine Milne says it is clear that tax avoidance by big business in Australia is endemic and that immediate steps must be taken to prevent further billions in tax being lost to the big end of town.

"Corporate tax avoidance in Australia is endemic. Big business is taking us all for a ride. We need more transparency, not more secrets," Greens Leader Christine Milne said.

With reports today that 10 companies together channelled more than $30 billion out of Australia in a single financial year, Australian Greens Leader Christine Milne says her Senate Inquiry into corporate tax avoidance couldn't start soon enough.

"It's time to make sure that as a nation we've got the money we need for health, for education and to look after our environment, rather than see these multinational corporations organise themselves to rip off Australia," said Senator Milne.

An independent costing requested by the Australian Greens and prepared by the Parliamentary Budget Office shows reducing superannuation tax concessions for the most wealthy would raise $10.16 billion dollars over four years.

"Government advisers have suggested it in the tax white paper, Labor says they'll support it and the Greens have got a costed policy that's ready to go. This would remove a tax haven and reduce the wealth gap between rich and poor, which would be a really great thing for Australians," said Greens Leader Christine Milne.

With the release of the tax white paper, you could be forgiven for thinking that the big end of town was doing it tough. But oh, how wrong you are. We've found 8 ways to raise revenue that the Liberal Party seem to be ignoring...

1. Abolish tax breaks for big mining

Currently big mining pays less for petrol than everyday Australians. How about if they didn't?

The Greens say any change to Australia's tax system must be progressive, correcting rising inequality and acting on global warming.

"The whole point of tax is to raise the revenue we need to pay for the Australian society we want: caring, innovative, healthy, and protected from the impacts of global warming" said Greens Leader Christine Milne.

"That means ending taxpayer support of polluting fossil fuels; it means actually collecting the tax owed by corporate Australia and multi-nationals, and it means closing tax loopholes for the richest among us.

Greens Leader Christine Milne says the thousands of people who've taken to the streets today for the March in March are crying out for a vision from Australia's political leaders, which delivers in the public interest, not just business as usual for vested interests.

"People are just so disillusioned. We all know we don't want the cruel cuts on offer from the Abbott government, but we also deserve better than a dull budget that preserves the status quo and holds Australia back," said Senator Milne.

The Greens say the Abbott government has destroyed all credibility in the Intergenerational Report process by ignoring global warming and with partisan politics. The Greens will move in the Senate to require the Parliamentary Budget Office to rewrite this and all future reports.

"There's nothing new in this report and it ignored global warming. It is pure politics and utter rubbish," Greens Leader Christine Milne said.

"It must be rewritten by the independent Parliamentary Budget Office in order to restore credibility to the Intergenerational Report process.