IT'S a difficult time to be a working Australian - you're either working hours of unpaid overtime or you're underemployed and struggling to get more shifts.

That's the bleak picture painted by a new report from The Australia Institute, which claims that both problems are caused by the casualisation of the workforce.

But employer groups say claims of increasingly insecure working conditions are overstated.

The report found millions of Australians are not paid for the extra hours they work, and the number of people working overtime is on the rise which causes stress and anxiety.

"Consistent with the idea that 'working smarter' is code for 'doing more with less' the survey results show a significant increase in the number of employees working unpaid overtime in the past five years," the report said.

In 2013, 60 per cent of workers said they are not paid for the extra hours they work, compared to 45 per cent in 2009.

The number of Australians who report being overworked is almost matched by the number of Australians who complain of underemployment.

The report found almost one quarter of respondents (24 per cent) would like to work more hours, compared to 28 per cent who want to work fewer hours.

Amanda Appathurai, 30, is a Melbourne-based child care worker who says underemployment is a big issue in her industry. Ms Appathurai has not had a shift for three weeks.

"I'm a diploma-qualified worker, I've in childcare for seven years plus working full-time previously," she said.

"I'm with two [childcare] agencies and I barely get any shifts at all even though I've got heaps of experience and good references."

Report author Prue Cameron says the increase in casual and non-permanent work is putting pressure on people to work harder for longer, and to work more hours unpaid.

"Because they just have to get the work done. I think it's because they've been contracted to complete a job and if the time allocated to the job doesn't match the demands of the job then they're just going to have to do the work anyway," Ms Cameron said.

Ms Cameron says there is mismatch between the demands of the workplace and what is achievable in normal working hours.

"It's part of the workplace culture. If their colleagues don't take a lunch break or their colleagues never go home on time then there's a lot of pressure," she said.

Australian Federation of Employers and Industries chief Garry Brack said businesses had to respond to downturns in the market.

"Look at any period of economic downturn, such as the period we have been in. Our labour costs are already so high we can't compete effectively in a lot of industries. But the union movement doesn't care about that."

Mr Brack says when fewer people are buying a business's services or products, they must pare back their workforce and other costs.

"Otherwise they go down the drain altogether and everybody loses their jobs," he said.

"It's not just employees they're cutting, they cut every additional shred of cost out of the business wherever they can."

Mr Brack added that the volume of people in casual employment hasn't changed much over time.

"The vast increase of casualisation that the Australia Institute and the unions argue exists doesn't exist at the level they talk about."

The AI surveyed 1409 people to get a better understanding of their experience in the workplace. The number of respondents who were employed at the time was 812.

###