Potentially hundreds of thousands of workers are being stymied in their careers by a dearth of part-time jobs at senior levels of management and leadership, according to the Workplace Gender Equality Agency.
A census of large employers undertaken by the agency found that just 7 per cent of management positions were part-time even though more than a fifth of the 4.8 million staff they employed were part-time.
Agency chief executive officer Mary Wooldridge said part-time workers essentially faced a "promotion cliff".
"Part-time workers who want to take up leadership roles in their workplace ... face a sudden drop-off in [the] availability of management level jobs that could otherwise contribute to to advancing or sustaining their career," Ms Wooldridge said.
The agency boss said this was a particularly acute problem for women, given that 30 per cent of them worked part-time, compared with 11 per cent of men.
"Limited access to flexible working arrangements has a disproportionate effect on women's earning capacity," she said.
"Women are more likely to want or need to work part-time. This analysis shows there are severe constraints on them doing so at senior levels and helps explain why we see much lower proportions of women in leadership roles."
The analysis follows the release of data showing the long-term shift in working arrangements away from solely full-time work toward more flexible and fewer hour forms of employment, including part-time and casual positions.
Australian Bureau of Statistics figures show the proportion of all workers employed in casual roles, defined as those without paid leave entitlements, has grown from less than 16 per cent in 1984 to 23.5 per cent in August last year, including more than 25 per cent of women in the workforce.
Ms Wooldridge said there was a perception that management positions, particularly at the senior levels, could not be part-time.
But she said around 150 of the firms included in the agency's census had chief executives and senior managers who worked part-time, which showed such views were mistaken.
"There has been this very strong message that there is a fundamental incompatibility between senior management roles and part-time work but in practical terms, the fact that we have got CEOs and senior managers in part-time positions shows that it can be done," Ms Wooldridge said.