Australia's upper house passed a controversial pollution tax on Tuesday in what the government called an "historic day" after years of bitter debate which felled a sitting prime minister. Cheers and applause broke out as the Senate approved the Clean Energy Act by 36 votes to 32, requiring Australia's coal-fired power stations and other major emitters to "pay to pollute" from July 1 next year. The laws -- 18 in total -- will now return for a final vote in the lower house, where they are expected to again be approved after winning approval last month 74 votes to 72. Deputy Prime Minister and Treasurer Wayne Swan said the passage through the Senate was a "victory for the optimists and... a defeat for the deniers." "Today is an historic day for economic reform," he said ahead of the vote. "No longer will the big polluters be able to pump carbon pollution into the atmosphere for free." The law's approval caps a tumultuous period in Australian politics, largely centred on what the vast nation -- one of the world's worst per capita polluters -- should do about carbon emissions linked to global warming. Former prime minister Kevin Rudd harnessed an unprecedented wave of popular support for climate change action, winning the 2007 election in a landslide after campaigning to ratify the Kyoto Protocol and take other green measures. But Rudd's plans were frustrated by entrenched conservative opposition which saw a proposed emissions trading scheme ultimately shelved, and his credibility was so badly damaged that he was ousted by Gillard in a Labor party room coup. Gillard went on to scrape back into office last year by forming a coalition with independent lawmakers and the left-leaning, eco-minded Greens, who won a record vote share in the first deadlocked national poll in some 70 years. Greens leader Bob Brown said that "even the heavens are clapping" after what he described as a landmark act of responsibility by Australia's parliament. "It's a green-letter day but it's one that will echo down the ages," Senator Brown told reporters.