The Australian Greens say they will be in a key position to amend mining tax legislation if, as expected, they hold the balance of power after the next federal election.

Any agreement between the mining sector and the federal government on Labor’s proposed resources super profits tax will be subject to parliamentary scrutiny, Greens leader Bob Brown told reporters in Sydney on Thursday.

“There’s a small thing called democracy here and a big thing called the Australian parliament, and unless Labor gets control of both houses, and that’s not going to happen, then the agreement will be subject to parliamentary scrutiny,” Senator Brown said.

The Greens do not want the current “very secret” negotiations between the government and the mining sector to result in any reduction of the $12 billion extra revenue forecast in the budget’s forward estimates.

“(Twelve billion) is a pretty clear guide to whether the government has maintained the public interest or caved in, and if so by how much it’s caved in,” Senator Brown said.

“Which other sector of the Australian community expects to have such a monumentally important tax item negotiated so rigidly behind closed doors and away from the view of public scrutiny?

“The mining industry needs to know that parliament has the final say, not just government.”

The opposition has no intention of supporting a deal, saying it will rescind the tax if it wins power at the next election.

Senator Brown reiterated that the Greens had no plans to block mining tax legislation introduced after the election.

“Tony Abbott is saying, `I’m a blocker.’ I’m not saying that, I’m saying we’re improvers, we’ll get better outcomes,” he said, citing the role of the Greens in last year’s economic stimulus package.

“We’ll be looking for the public dividend here. We’ll be looking for the interests of small business and Australians generally.”

Senator Brown said he was hopeful of improved dialogue between Labor and the Greens under the new prime minister.

“I’m expecting with Julia Gillard now in the pilot seat of government, we’ll get a better direction in terms of a two-way dialogue on important issues, particularly with … the Greens likely to get the balance of power in the next election,” he said.

If the election resulted in a Labor-controlled lower house and a Liberal-controlled Senate, there would be “gridlock”, Senator Brown said.

“And that’s a very poor outcome for the Australian people.”