A crackdown on citizenship rights for children of migrants and foreign diplomats is among a number of dumped Tony Abbott-era proposals to have resurfaced in the Turnbull government's citizenship revamp.
The government says the restrictions are necessary to stop parents using their children's citizenship "as an anchor for family migration" or to win sympathy in their own migration disputes.
Under the proposed changes, children will no longer become citizens on their 10th birthday if, at any point, they were present in Australia unlawfully or re-entered Australia without a valid visa.
The same will also apply if a child's parent lacked a "substantive" visa at the time of the child's birth and was present in Australia unlawfully prior to the birth. That means a child born to parents on bridging visas would not automatically acquire citizenship.
And children born to foreign diplomats will no longer gain Australian citizenship on their 10th birthday.
However, the immigration department confirmed to Fairfax Media that in each case, if one of the child's parents was an Australian citizen or permanent resident, the child would acquire citizenship in the normal way.
The crackdown, revealed in legislation introduced by Immigration Minister Peter Dutton on Thursday, mirrors measures included in a 2014 bill that never passed the Senate and eventually lapsed.
That bill, drafted when Scott Morrison was immigration minister, also gave the minister controversial new powers to cancel citizenship and overrule decisions of the Administrative Appeals Tribunal.
Australian National University expert Kim Rubenstein, who objected to the 2014 proposal, said the refreshed attempt was "another step backwards".
"It distorts the balance in terms of creating a cohesive society - anyone who's a migrant is seen to be taking advantage of this country," she said.
"It's a very, very spurious type of motivation in my view. It smacks of developing citizenship policy purely as migration policy."
The bill's explanatory memorandum states the changes are designed so that "people who do not meet the proposed requirements will no longer have an incentive to delay their departure from Australia until a child born to them in Australia has turned 10 years of age, in the expectation that the child will obtain citizenship and provide an anchor for family migration or a justification for a ministerial intervention request under the Migration Act".
In 2014, the Department of Immigration and Border Protection said an average of 400 children a year applied for citizenship under the so-called 10-year rule, mostly from South Korea, New Zealand, China, Japan, Indonesia, Fiji and Tonga.
Mr Dutton said the changes would not affect children who are stateless or born to New Zealand parents. He told the Parliament the bill "reinforces the integrity of our citizenship program" and would "help maintain strong public support for migration ??? in what is an increasingly challenging national security environment".
Mr Dutton has challenged a hesitant Labor opposition to support the citizenship package, and seized on reports the party is split over several of the measures.
Labor has insisted on inspecting the legislation in detail, which will now be considered by the party's leadership group, shadow cabinet and caucus.
Mr Dutton has also indicated he is willing to negotiate with the Senate crossbench. Crucially, Nick Xenophon, who controls three Senate votes, has previously said he is "broadly supportive" of the government's proposal.