Treasurer Jim Chalmers has defended the government's decision not to add questions about gender to the census, saying it was concerned about it being weaponised against the LGBTIQ community.

It comes as the sex discrimination commissioner urged the government to reconsider its decision in a letter to Assistant Treasurer Andrew Leigh, stating that it carried serious implications for the wellbeing of the LGBTIQ+ community.

The decision to back away from plans to count sexuality and gender-diverse Australians was first revealed on Sunday.

The treasurer, speaking to ABC RN on Thursday, said that the government's goal had been to "try and avoid some of the nastiness that sometimes accompanies that in the lead-up to the census". 

"My fear, and one of the things that's guided us here ... is we've seen the way these issues can be weaponised against members of our community and we don't want to see that happen," he said. 

He did not answer questions about whether the government would consider reversing the decision given the feedback from the community, but noted that the census is still two years away. 

"I'm not here to flag that, I'm here to explain how we got here and why," he said.

"We want to avoid the nastiness and weaponisation of these issues."

His comments followed those by Deputy Prime Minister Richard Marles, who told reporters on Wednesday that the plan was capped to avoid a "divisive debate".

"The last thing we want to do is inflict that debate on a sector of our community right now," Mr Marles said. 

The comments echo the reasons Prime Minister Anthony Albanese gave for shelving the contentious religious discrimination reform earlier this month.

Opposition Leader Peter Dutton also waded into the debate on Thursday, stating that he felt the current census questions were satisfactory. 

"If you've got the woke agenda, which I think is at odds with the majority of Australians, then the prime minister should argue that case," he said.

Advocacy groups outraged 

The decision not to proceed with the new questions has angered LGBTIQ advocates who say they have a right to have their identities included in the national survey. 

"What the government is saying to us is that we are not worth having the hard conversations for, and they are dumping us in the too hard basket," Equality Australia chief executive Anna Brown said on Thursday.

In response to the government's concerns about the potential for divisive debate, she added: "The notion that acknowledging the existence of LGBTIQ+ Australians in the census would be a threat to social cohesion is, frankly, absurd.

"And it is insulting to all Australians to think that they would be in some way angered or divided by such a basic acknowledgement of fact." 

Labor's 2023 policy platform — released before the last election — includes a commitment for the 2026 census to collect relevant data on LGBTIQ Australians. 

That commitment followed a push from Equality Australia and community member April Long, who submitted a complaint to the Australian Human Rights Commission that claimed the omission of LGBTIQ data collection from the census was discrimination. 

The chief executive of LGBTIQ+ Health Australia, Nicky Bath, said without population data for gender and sexuality-diverse people they're "kind of working with blindfolds on". 

If the questions are not included in the next census as planned, she said, it will mean this continues until at least 2032, when the next set of data will be available. 

"These simple questions will actually enable us to be able to target services and target responses in a way we're just not able to at the moment," she said.

Calls for decision to be reversed

Sex discrimination commissioner Anna Cody echoed Ms Bath's concerns, stating that collecting data about LGBTIQ people was a "matter of practical, effective policy".

"The aim of the census is to capture a snapshot of Australia, and the data it generates is vital for ensuring services and policy reflect the needs of our country's diverse populations," she said. 

"While we must seek to minimise harm, the answer cannot be to do nothing."

A group of crossbench MPs have also expressed their dismay in an open letter to the government that urged it to reconsider.

The letter was spearheaded by independent Allegra Spender and signed by her fellow teals, as well as Helen Haines, David Pocock, Andrew Gee and Andrew Wilkie.

"Excluding LGBTIQA+ people and ignoring the evidence that demonstrates the need for this data will impact negatively on people's lives for many years to come," it read.