CANBERRA, Australia, Sha'ban 01, 1437, May 08, 2016, SPA -- A two-month Australian election campaign is expected to officially start on Sunday, with climate change, climbing house prices, company tax rates and union corruption in the national building industry shaping into the key issues, according to AP. Prime Minister Malcolm Turnbull, who heads the center-right Liberal Party, has said he will likely tell Governor-General Peter Cosgrove to lock down a July 2 election date this weekend and trigger the unusually long campaign. He and Bill Shorten, leader of the center-left Labor Party, recently outlined their conflicting economic policies on how Australia should rein in mounting debt without slowing an already sluggish economy. Neither Turnbull nor Shorten has ever led his party into an election campaign before. A heartening historical fact for Turnbull is that no Australian federal government has lost power after a single three-year term since the tumultuous early years of the Great Depression. But Australia is now in an extraordinary era of political volatility as it grapples to diversify an economy that thrived on a mining boom that has gone bust. If Labor wins the election, it would mean Australia's fifth change of prime ministers in six years. Turnbull replaced his unpopular predecessor, Tony Abbott, in a leadership ballot of lawmakers in the Liberal Party in September, only two years after the coalition government was elected. The change of prime ministers immediately boosted the government's standing in opinion polls, but recent polls suggest the government is now running neck-and-neck with Labor. The government has released its budget plans for the next fiscal year, which begins on the eve of the election, calling for stimulus measures including income tax cuts for middle- and high-income earners and a gradual reduction of the company tax rate over a decade from 30 to 25 percent. Shorten's Labor Party opposes most of the tax cuts and would spend the money saved on hospitals and schools. Shorten said the government's budget was crafted for "Malcolm's millionaires" and offered nothing for the poor. He accuses Turnbull, a 61-year-old self-made multimillionaire, of being out of touch with ordinary folks. The government accuses Shorten, a 48-year-old former union boss, of inciting divisive and outdated class warfare. A crucial election issue for many Australians is the policy differences on the Australian housing industry, which is a major strength of an economy hit hard by the Chinese slowdown and the associated lower prices for iron and coal — Australia's most lucrative exports. Many analysts agree that housing is overpriced in major cities including Sydney, and that the proportion of Australians who can afford to buy their own homes is shrinking. Labor wants to reduce tax breaks on real estate to make it a less attractive investment for landlords. The plan is that investors won't price as many would-be owner-occupiers out of the housing market. But the government has warned that property prices would tumble and damage the economy. Ostensibly, Turnbull has called an early election because a hostile senate has refused to pass legislation that would allow the government to create a building industry watchdog called the Australian Building and Construction Commission. The ABCC was disbanded in 2012 by a former Labor government linked to the trade union movement. While the plight of the ABCC seems an obscure issue to most voters, the political debate focuses attention on Shorten's history as a union official. Before he entered Parliament in 2007, Shorten was a senior official of the Australian Workers Union, one of five unions targeted by a government-commissioned inquiry into union corruption. Labor condemned the inquiry as a politically motivated witch hunt. Shorten rejected suggestions by inquiry lawyers that he had had conflicts of interest when companies made donations to his union while he was negotiating with them over workers' pay. Even Labor supporters criticized him over news of the donations. Australian National University political scientist John Wanna expects Turnbull to use the issue to focus on Shorten's union past during the campaign. "He's going to turn the attack on Shorten: 'You're just a union thug; you're just a union hack; you've blocked us from bringing in a measure that would have made unions more accountable,'" Wanna said. Labor is expected to exploit Turnbull's past support for Australia's adoption of an emissions trading scheme to cut greenhouse gas pollution. Australia, on a per capita basis, is among the world's worst polluters. Turnbull's support in 2009 for a Labor government proposal to introduce an emissions trading scheme cost him the leadership of the Liberal Party. He was replaced by Abbott, who repealed a 2-year-old carbon tax in 2014. The tax paid by Australia's worst industrial polluters had been due that year to transition into an emissions trading scheme, with market forces determining the price of a ton of carbon. Labor again wants the emissions trading scheme to replace the government's so-called Direct Action policy of paying polluters taxpayer-funded incentives to operate more cleanly, and Shorten has been reminding the public that Turnbull once described Direct Action as "an environmental fig leaf to hide a determination to do nothing." --SPA 03:30 LOCAL TIME 00:30 GMT www.spa.gov.sa/w