Australian Greens Leader Bob Brown says the government could be setting an example to the world with an efficient tax to ensure Australians get a fair share of the returns from the nation's mineral wealth, and putting aside some of the proceeds in a sovereign wealth fund for the needs of future generations.

 "Australia should take this opportunity to put in place an efficient, forward-thinking resources rent tax that reaps a fair share for this and future generations," Senator Brown said today.

 Australia is a low-taxing country with scope to increase taxation revenues to ensure our future prosperity, Australian Greens leader Senator Bob Brown said today

"The government has imposed a target on itself of keeping the ratio of tax to GDP below the 2007-08 ratio of 23.7 per cent but in the coming year the ratio is predicted to be only 22.3 per cent," Senator Brown said.

 "If the government kept to its target we would have an extra $22 billion to deal with the challenges facing us.

The government's mining tax is now expected to pass parliament before the end of next week.

In a late afternoon press conference, Greens leader Senator Bob Brown confirmed a deal with the government had been secured in talks today.

The Greens have agreed to give the contentious mining tax the backing it needs to pass the senate during the current two week parliamentary sitting and in return, the government will make public its planned company tax cuts legislation tomorrow.

Australian Greens Leader Bob Brown spoke to ABC News Radio's Marius Benson this morning about the diminished mining tax and government's headlong rush to try to get it through the Senate.

We're not going to be rushed on this legislation. The government must show the Senate the full mining tax package, Senator Brown said by phone from Hobart.

Bob Katter's out-of-date, tawdry advertisement against equal marriage was also discussed.

Australian Greens Leader Bob Brown says the Gillard government has itself to blame if the Senate delays passage of the mining tax package in coming weeks.

"Where is the government's promised tax cut for small business (from 30% to 29%) due to start in July? It is reasonable to want to see legislation for the small business tax cut before handling the rest of the package," Senator Bob Brown said in Hobart today.

The Treasurer’s questioning of charities' tax deductibility status must be matched by questions to business organisations, Australian Greens Leader Senator Bob Brown said today.

"The Treasurer’s questioning of certain groups' tax deductibility status shows a bias towards mining and business interests," Senator Brown said.

“I will be asking the Treasurer to ensure that any mining company contributions to business organisations are questioned before any assault on environment groups," Senator Brown said.

We should encourage, not vilify, the attempt by concerned citizens to make the mining public policy debate less lop-sided, Australian Greens Leader Bob Brown said today.

"We see full page ads coming from the mining billionaires at the moment, proving the point about vested interests throwing their weight around and skewing public policy. There is a lopsided public discourse going on. The green groups are adding balance. Good on them," Senator Brown said in Sydney.

Australia should secure its future with a fair dinkum mining tax, Australian Greens Leader Bob Brown said today.

"Treasurer Wayne Swan is right. Australia's fair go is under threat," Senator Brown said in Hobart.

"Australia can fund its education needs - including the $5 billion proposed by the Gonski review, health services, public transport, a national dental program and high speed rail. There is an additional $100 billion available over the next 10 years if we implement the original super-profits tax," Senator Brown said.

Australian Greens Leader Bob Brown, part way through the Senate inquiry into the minerals resource rent tax, spoke to reporters in Canberra today, calling for the mining tax to be extended to gold and uranium.

The anniversary of the Christchurch earthquake, the Greens' move for a Senate inquiry into the draft Murray Darling Basin plan, equal marriage, nuclear submarines, and the Labor leadership saga were also discussed.