He told The Sun-Herald he believed his party had been given a mandate by voters to force change on a broad range of social and environmental issues.

Senator Brown, whose party will help hold the balance of power from Tuesday, will lay out his plans about the "very different days" ahead to the major parties during the eight-week winter break.

"The Rudd Government has the bigger agenda, it's got that mandate. We have a much smaller agenda, but we have a qualified mandate, too," he said.

"We went to the election with a whole range of policies, and some of those are going to be legislated.

"I'm not here for a holiday; I'm not here to play shuttlecock."

Senator Brown has an even bolder vision for the Greens.

"We're not shy about saying our job is to replace the big parties in the long run," he said.

The party would be "energetic and innovative". He wanted the Senate, whose traditional role is to review legislation passed by the House of Representatives, to become a "house of innovation".

Senator Brown declared his party would play a radically different role to the Democrats.

"We're not going to sit here waiting for the next Bill to land on our desk to see if it's got any mistakes in it," he said.

"And we're not here to adjudicate between the big parties. It's not about keeping the bastards honest. We're not a referee - we are on the field playing."

One of Senator Brown's first acts will be to seek to return to the Northern Territory and the ACT the right to pass laws to allow voluntary euthanasia, rights stripped away by the Howard government.

It overturned the Northern Territory's voluntary euthanasia law in 1997, and usurped the ACT's right to pass similar legislation.

Senator Brown's Bill would restore those Territories' rights, and it would then be up to them if they wanted to pursue such legislation, he said.

He believed the Bill would receive support in both houses in the new sittings.

The new Senate, with five Greens senators holding the balance of power with the South Australian independent Nick Xenophon and Family First's Steve Fielding, will hold its first parliamentary sittings in late August.

The Greens will also introduce or amend laws to:

* Restore the Racial Discrimination Act, sidelined by former prime minister John Howard when he launched the Northern Territory intervention into indigenous communities;

* Impose a 25cent levy on plastic bags and look at the possibility of national container legislation to curb the use of plastic bottles;

* Disallow the excise rise on so-called alcopops unless the Government pumps money into other anti-binge drinking measures; and

* Allow "above the line" preferences in Senate elections to halt backroom preference deals. "People themselves will decide where their preferences are going," Senator Brown said.

The Greens would lobby "very hard" to pump billions of dollars into public education and increase pensions by between $30 and $100 a week, he said.

"I think that in the next budget next year, because of the Greens' campaign, we will see a rise in the pension. I'll take any opportunity in the meantime to get a $30-a-week lift in the single pension."