Australia's public sector is meant to set the national standard for promoting gender equality in the workplace.
But inside government departments, Four Corners has uncovered accusations of discrimination against mothers and pregnant women who work in public sector roles.
These women described being demoted, denied flexibility, turned down for promotions, and refused a comfortable place to breastfeed.
Some were made redundant or let go after they fell pregnant or took parental leave.
And it's not just a handful of cases.
They were among more than 100 women who told Four Corners they had experienced discrimination at work after falling pregnant or having children as part of a wider investigation.
Former high-ranking counterterrorism official denied flexible work
Until June, Alisha Warner was a counterterrorism senior executive in the Department of Home Affairs, one of Australia's most powerful government departments.
For nine months, before going on leave for her second baby, Alisha had a flexible arrangement in which she worked full-time hours over four days.
"When I mentioned that I was looking to come back on the same arrangement … I was surprised to be met with an immediate response that senior executives cannot work flexibly," Alisha told Four Corners.
"I was really shocked and a bit concerned immediately about what that was going to mean."
Documents obtained under Freedom of Information laws show Alisha's managers asked Human Resources for advice about Alisha's request to return on compressed working hours.
The department had "reasonable business grounds" to reject Alisha's flexible request, the advice said. However, it acknowledged it was "arguable" that Alisha's four-day arrangement "remains in place".
When asking for a response to be prepared to send to Alisha, a department official said, "Confirming the intention is not to support the request, so I'd be grateful for a response on that basis".
Managers at the Department of Home Affairs rejected Alisha Warner's request. (ABC News: Matt Roberts)
The department offered Alisha a short transition period but after that, required her to work five days a week.
"Going back full-time [over five days] is not always an option. In my case, I can't get another day of child care for my children," she said.
"I was very strongly given a message that flexible work was not going to be supported anywhere."
Alisha's managers said they needed someone in her role five days a week, because the counterterrorism space had changed.
"The scope, complexity and sensitivity of the responsibilities assigned to the relevant role under consideration evolved post the Bondi terrorist attack, and now require sustained senior executive level oversight, leadership and decision-making," a Home Affairs spokesman told Four Corners.
"Accordingly, the department was not in a position to approve compressed hours."
Alisha said she was surprised to hear this response.
"In my previous arrangement, I was available whenever needed on that day off for anything critical," she said.
"There [were] lots of assertions made about how busy the role was, but to be honest, not a lot of real tangible evidence or information about why it couldn't be performed under the same arrangement."
Alisha eventually took a voluntary redundancy and was asked to sign a confidentiality agreement, which she refused.
"A lot of people are forced into signing non-disclosure agreements, and that has led to a complete dark hole of people feeling like they're alone in what has happened to them," she said.
Looking back, Alisha said she did not want to leave her job.
"It's not a real choice when you don't feel like you have any other choices," she said.
"The thought of leaving a full-time, secure, senior executive role that I worked so incredibly hard to get filled me with absolute dread."
Former senior government official supports increased flexibility
In a rare interview, former assistant commissioner of the Australian Border Force, Kylie Rendina, said some managers in the public service viewed flexible work arrangements as too costly.
However, she said it was often a greater financial loss for an agency to lose a staff member who needed flexibility.
"Sometimes, the people who are making the decisions at all levels don't really have a good understanding of the costs of losing a resource and retaining a resource," she said.
Kylie Rendina managed workplace culture at Border Force until she left the role in January. (ABC News: Rob Hill)
Analysis shows replacing an experienced staff member in an organisation could cost 50 to 200 per cent of an annual salary, Ms Rendina said.
Now working as a consultant in the public sector, she called on agencies to change their attitudes toward flexible work arrangements to keep up with the demands of raising a family.
"We didn't need the flexibility that we want today, probably largely based on one parent being at home a lot of the time,"
Ms Rendina said.
"That's just not reality anymore."
A Home Affairs spokesman denied there was a culture of denying flexible work arrangements due to cost, but acknowledged it was a factor.
"Any expenditure of resources, including the engagement of staff, must be considered within the department's budget and in accordance with its obligations under the Public Governance Performance and Accountability Act," he said.
Employment Minister Amanda Rishworth said the Australian public service, including the federal government, aimed to be a "model employer".
Amanda Rishworth says the public service should set a high standard. (ABC News: Matt Roberts)
"We've got to make sure that we're not suggesting just because you're taking flexible work, that somehow you're less productive or not contributing," she told Four Corners.
"That's a bit of an outdated stereotype.
"We've got to make sure that everyone is promoting those conversations, but there is a right for flexible work."
Alisha took action against the Department of Home Affairs in the Fair Work Commission, alleging a breach of the flexible work provisions.
The mediation ended without agreement, and she decided not to escalate her claim to the Federal Court.
"I strongly believe in my case, but I also know how much lawyers cost," Alisha said.
"The biggest disappointment for me is the message that [my story] sends to all the other women coming up through the ranks in the public service, who are already thinking, 'I have to hold myself back if I want to have kids.'"
Watch Four Corners' full investigation, The Pregnancy Penalty, tonight at 8:30pm on ABC TV and ABC iview.