The slowdown in China and a tighter federal budget will pull Australia's growth down to as low as 2 per cent next year, prompting interest rate cuts and a 20 per cent slump in the value of the Australian dollar, a prestigious global forecaster says.

Roubini Global Economics, founded by renowned US economist Nouriel 'Dr Doom' Roubini, says slowing Chinese growth will hit commodity prices and Australian export volumes, while domestic consumer and investment weakness will continue to drag on the country's gross domestic product.

The Australian dollar is headed for further falls, according to Roubini Global Economics. Credit:Glenn Hunt

Dr Roubini himself earned the "Dr Doom" moniker through consistently bearish analysis, exemplified by his accurate prediction of the 2008 US housing market crash and the global financial crisis that precipitated from it.

The Roubini report describes the federal government's fiscal austerity as "poorly timed" and sees GDP growth slowing from just below 3 per cent to below 2 per cent for 2015, after ending this year at 2.9 per cent.