Millions of Australians are struggling to work more hours and lift their earnings in a "gig economy" that suppresses wage growth, according to new research that reveals key pressure points across the country.

The nation’s outer suburbs and regions are suffering most from the barriers to greater employment, in a challenge hidden by the nation’s headline 5.3 per cent unemployment rate.

Today, an estimated one-third of the workforce work part-time.

Labor will cite the research on "under-utilisation" to warn on Sunday that about two million Australians are not getting what they need from the labour market.

Labor frontbencher Clare O’Neil will liken the trend to a "drought" for workers who need more work, saying the two million Australians "want to have a go but can’t get a go" under the Morrison government.