‘Enough is enough,’ Greens Leader Adam Bandt declared to the National Press Club in Canberra last Wednesday. ‘It’s time to make the big corporations and billionaires pay their fair share of tax.’ As well as seeking to close ‘loopholes’ in the existing petroleum resource rent tax, his party is proposing a ‘supertax’ – a 40 per cent tax – on the profits of coal and gas corporations and, more broadly, on any annual corporate profits of more than $100 million.