Owen Wareham, was nervous about asking to reduce his hours in a marketing job after his daughter Harriet was born nine months ago. But his Sydney employer has been very supportive in allowing him to reduce his hours from five to four days a week at its Brisbane office.

The arrangement allows him to care for Harriet one day a week and his wife cares for her two days, with the remaining two days spent in childcare.

Mr Wareham plans to eventually return to five days a week when Harriet is older.

"I was quite apprehensive about asking at first, but once I asked everyone at work was supportive, so it was pretty straightforward," he said.

"Part of the reason I wanted to do it was our baby is a little girl and I wanted to model good behaviour her. I didn't want her to grow up only seeing women as carers."

A new survey has found 60 per cent of more than 5400 Australians surveyed have never asked for reduced hours to assist with family life and caring responsibilities with many citing job security or a workplace culture that does not support flexible work.

It also found that almost 40 per cent of workers have asked their employer for reduced hours for caring and almost a quarter of had been knocked back. Employers were 50 per cent more likely to reject a male worker's request for reduced hours.

The Australian Council of Trade Unions, which commissioned the survey, has applied to the Fair Work Commission for a new entitlement for all workers to temporarily reduce their hours to help them manage parenting or other caring responsibilities.

The Commission will hear the case in December and determine whether all modern awards should be changed to provide employees with an entitlement to reduce their hours for a period before returning to full-time work.

ACTU President Ged Kearney said many people are stopped from providing family care because workplace laws and rules had not kept up with modern life.

"Whether a dentist in Newcastle, a security guard in Sydney or a teacher in Melbourne, working women and men have told us that juggling both caring for family and working is a major issue for their lives," Ms Kearney said.

"The cost on individuals and families is enormous, with some survey participants estimating they are doing in excess of $50,000 a year in unpaid caring for a family member.

"Many of the survey respondents said their workplace culture was not flexible and others said they did not ask their employer for reduced working hours because they feared they would get sacked. This is the disgraceful reality of our modern workplaces."

In its submission to the Fair Work Commission, the ACTU argued that access to flexible working arrangements is arbitrary and unable to be enforced or when granted, can involve a downgrading in the status or security of their work.

The ACTU submission to the Fair Work Commission says that for too long the starting point for accommodating family responsibilities has been the assumption that all employees will be available to work full-time and a case needs to be made to departure from that norm.

"The ACTU's application seeks to tilt the starting point to a more equitable and realistic position, where it is accepted that employees must reconcile work and family responsibilities, and to align workplace norms to the reality of workers' lives," the submission says.

It will on Sunday launch a new campaign to "change the rules for working women and families", with its new survey results showing that 85 per cent of working Australians also have significant family caring and/or parenting responsibilities.

"The ACTU wants a new right for all Australian workers, especially women who predominantly carry the caring load, to have the right to part-time or reduced hours temporarily while they have important family caring responsibilities," Ms Kearney said.

"We are using all our legal options to make this a reality for working women and families."

ACTU survey findings:

??? Almost 85% of Australians have or have had a caring role;

??? 65% had cared for a child of school age or younger

??? 27% had cared for someone frail or aged

??? 25% had cared for someone with a medical condition

??? 14% had cared for someone with a mental illness.

??? Almost 40% of workers have asked their employer for reduced hours for caring and almost a quarter of these had been knocked back;

??? Almost one in two workers needs access to reduced hours for caring;

??? Women are almost twice as likely to ask for reduced hours for caring;

??? Employers are 50% more likely to reject a male worker's request for reduced hours;

??? Inflexible workplace culture is the reason most cited for workers not asking for reduced hours to care for a family member;

??? Nearly one in five workers surveyed was not able to access reduced hours needed for caring responsibilities.