Domestic violence leave provisions for female workers would be a barrier to women getting jobs, according to the Minister for Women, Michaelia Cash.
Senator Cash told an election campaign event in Victoria on Friday morning that the entitlement might act as a "perverse disincentive" to employers considering hiring women.
The minister's comments were immediately condemned by Labor as "callous" and by the main public sector union as "exposing the Turnbull government's anti-women agenda".
Campaigning in the Victorian marginal seat of Bruce on Friday, the minister was asked about the CPSU's campaign to get specified domestic violence leave into public service workplace agreements.
"I think you have to be very careful as a policymaker in saying to businesses, an employee can now take an additional four weeks leave that you pay for," Senator Cash said.
"Do you put in a perverse disincentive that 'I just won't employ women'?"
The minister and union have been locked in a bitter dispute since March over the issue with public service departments following instructions, sometimes against their will, to reject the union's proposals for specified domestic violence leave in enterprise agreements.
The Department of the Prime Minister and Cabinet was forced to remove an explicit reference to domestic violence from its proposed enterprise agreement and Senator Cash has rejected a plea from the Human Rights Commission to reconsider her stance.
The government has argued that existing leave provisions are enough to cover public servants if they need time off work after being victims of family violence, while the CPSU's position is that the public service should offer similar provisions as large employers such as Telstra, NAB, Virgin Australia and IKEA.
CPSU national secretary Nadine Flood said the minister's comments were "beyond bizarre".
"Minister Michaelia Cash has finally let the cat out of the bag, showing the Turnbull government is saying one thing in spruiking its support for domestic violence victims while its actions do the opposite," Ms Flood said
"We've been calling for months for Michaelia Cash and Malcolm Turnbull to explain why they won't allow domestic violence leave to be added to new Commonwealth enterprise agreements, as has been done by a number of high profile private companies.
"This excuse is beyond bizarre.
"Senator Cash is saying the Government can't do the right thing by women working for the Commonwealth because it would encourage the private sector to illegally discriminate against women."
Labor's employment spokesman Brendan O'Connor joined in the criticism of Senator Cash on Thursday, saying she had walked away from a bipartisan approach to domestic violence.
"Senator Cash's comments completely contradict the bipartisan commitment to addressing the scourge of domestic and family violence," he said.
"It's yet another example of this government saying one thing by lauding companies who have committed to domestic and family violence leave and doing another by actively railing against it."
"This is clearly demonstrated by the Abbott-Turnbull government's public service bargaining framework, which forces agencies to strip things like domestic and family violence out of agreements and put them into policy which can be changed on a whim.
"A Shorten Labor government will make domestic and family violence leave a universal workplace right, by providing for five days paid domestic and family violence leave in the National Employment Standards."