The coalition put forward a proposal on Sunday that would criminalise facilitating the re-entry of people with IS links to Australia.
The opposition criticised Labor of being complacent about the possible return of a group of 34 wives and children of former IS fighters, who have been held in a Syrian camp since the militant group's defeat.
While one person from the group has been given a two-year temporary exclusion order barring their return, other members of the so-called "ISIS bride" cohort have been granted Australian passports as they are citizens.
Health Minister Mark Butler said the opposition's policy wasn't serious, labelling it a "grab for a headline" that could potentially capture aid workers.
"All we've seen is newspaper articles about (the policy)," he told ABC TV on Monday.
"No serious content about what appears to be some plans to try and criminalise the work of aid organisations like Save the Children.
"We're focused instead on applying the strict letter of the law."
The opposition's proposal would apply in circumstances where the government has given "express permission" for repatriation to occur.
The federal government has ruled out any efforts to repatriate the group.
Opposition foreign spokesman Ted O'Brien said non-government organisations could be captured under the proposed laws, adding there is no automatic exemption for those who help children.
"To the extent that they are assisting foreign fighters, families or sympathisers of terrorists, yes it would," Mr O'Brien told ABC Radio.
"To the extent that they are providing humanitarian services, no it would not."
Self-managed returns of the women and children was a loophole that needed to be closed, he added.
"Under that arrangement, it permits non-government third parties to organise terrorists and their affiliates to enter Australia, and they can do that on their own without government oversight," Mr O'Brien said.
"So this proposed law closes that loophole, brings back responsibility to lie with the government and doesn't allow the government to effectively outsource the repatriation of terror sympathisers back to Australia."
Assistant Foreign Affairs Minister Matt Thistlethwaite said Labor has "toughened up" laws surrounding ISIS fighters and their partners being allowed into Australia.
"If anyone is advised by the security and intelligence agencies to have been involved in potential terrorist activities, they'll be excluded," he told Sky News.
Opposition home affairs spokesman Jonathon Duniam said conditions imposed on previous citizens with links to IS would not be adequate for the current cohort.
In 2022, four women and 11 children were returned to Australia, while eight orphaned children were repatriated from Syria in 2019 under the then-coalition government.
"With those who have been repatriated, who have faced prosecution in the past, the best we got was a good-behaviour bond for 25 months," Senator Duniam said on Sunday.
"These are people that went to Syria to support a death cult."
The coalition has called for laws to be strengthened to stop the cohort from accessing Australian passports.
Attorney-General Michelle Rowland said any laws would need to be created in consultation with intelligence and security agencies, and that there are protections in place if the 34 women and children re-enter Australia.
"This is a cohort that has been monitored for years by our agencies," she told ABC TV.
"It is put forward that if they have committed crimes, they will be subjected to the full force on the law."
