The gas export hub at Barrow Island, of northern Western Australia. The massive disparity – and prospect, first revealed by Fairfax Media, that Australia will receive no significant take from LNG for "decades" – has sparked calls for a public inquiry into the the petroleum resource rent tax or PRRT. A letter co-signed by 21 left-leaning organisations and unions, including the ACTU, ActionAid, Greenpeace, the Australian Council of Social Service and the Uniting Church, has been sent to Prime Minister Malcolm Turnbull by the Tax Justice Network urging a Parliamentary inquiry into PRRT. "The undersigned organisations have major concerns about forecasts of declining or stagnant government revenue from PRRT coinciding with Australia becoming the world's largest exporter of LNG," the letter states. "The PRRT system, based on voluntary compliance and and self-reporting [by gas extractors], operates with limited transparency and inadequate oversight. Australians need greater public confidence that they will benefit fairly from the exploitation of our natural resources."

Treasurer Scott Morrison responded on behalf of the government on Sunday. "The government constantly monitors our tax system to ensure it keeps up with changing circumstances and will make reforms where necessary," said his spokesman. Labor, which is being lobbied to facilitate a parliamentary inquiry, is formulating a position, said shadow assistant treasurer Andrew Leigh. The 2010 Henry tax review warned that the PRRT "fails to collect an appropriate and constant share of resource rents from successful projects due to uplift rates that over-compensate successful investors for the deferral of PRRT deductions". In essence, the write-offs available for investors in mega LNG projects like Chevron's $70 billion Gorgon facility in Western Australia are too generous. An example is exploration costs that are allowed to compound at an annual uplift rate of 18 per cent each year before they are written off against profits, sometimes years later.

In April, Fairfax Media revealed documents prepared for the WA Treasury that warned the Commonwealth would wait "decades" to receive any significant revenue from Gorgon, Chevron's other giant project Wheatstone and Woodside's Pluto gas field. When it was lobbying for approval, Chevron promised $338 billion would flow from Gorgon to government revenue by 2040. Diane Kraal, an expert in resource taxation from Victoria's Monash University, said she doubts that the multinational LNG companies will pay a dollar in PRRT "in her lifetime" unless the system is toughened. In 2005, the federal government collected $1.9 billion in PRRT, mainly from oil operations in Bass Strait. Last year, despite the explosion in LNG projects, revenue fell to $1.4 billion and the 2016 budget projected that to wilt to $800 million a year by 2020 when Australia becomes the world's biggest single exporter. A revenue comparison done for the International Transport Workers' Federation by Tax Justice Network member Jason Ward using Qatar government data and forecasts by the International Monetary Fund, found Qatar, which boasts the highest per capita income in the world, either negotiates a flat royalty rate on production or takes an economic stake in an LNG project before approval.

Qatar levels a 35 per cent tax rate on companies in the petroleum sector. On average, the Arab state receives about 23.5 per cent of the value of export revenues and is using that wealth to subsidise the diversification of its industry. Loading In 2015 alone, Mr Ward found, Shell, which is a one-third partner in one of the eight biggest LNG projects, paid $1 billion in taxes and fees to Qatar. "It is truly phenomenal that we are not benefiting from a finite national resource like LNG. A profits-based system like PRRT makes sense in theory but in practice a straight up royalty delivers. We all know by now how good multinational companies are at keeping their profits from sight," said Mr Ward.