The economy looks set to record its worst annual result in two decades as key economic indicators slump and pressure mounts on the Reserve Bank of Australia (RBA) and the federal government to pump out stimulus.

Prime Minister Scott Morrison said he expected national accounts data due on Wednesday to show the June quarter had been "very difficult".

PM Scott Morrison has told Australians this week's June-quarter GDP result will be weak but to expect a lift in coming months. Credit:AAP

The unusually pessimistic intervention follows mounting domestic and global headwinds that are expected to see economic growth stall at just above 1 per cent for the year to June 30, lower than during the depths of the global financial crisis.

The economy will need to have grown by 0.8 per cent for the quarter to beat the 1.7 per cent recorded in the 2008-09 financial year. But markets believe there are downside risks to the average forecast growth rate of 0.6 per cent, leaving policy makers facing the worst result since 2000, when the global economy was hit by the collapse in technology stocks.