Tasmania's transgender community is celebrating after landmark reforms to make gender optional on birth certificates passed their last parliamentary hurdle.

Key points: Parents in Tasmania won't have to list a gender on birth certificates

Parents in Tasmania won't have to list a gender on birth certificates 16-year-olds and older will be able to change their registered births

16-year-olds and older will be able to change their registered births Transgender campaigner Martine Delaney says the change "will save lives"

Tasmania's Lower House passed the Marriage Amendments Bill on Wednesday, after Liberal speaker Sue Hickey voted with the Opposition parties to allow debate.

The legislation had already been ticked off by the Legislative Council, but the government had sought to delay bringing on the bill in the Lower House for its final debate.

Sue Hickey went to the Opposition side on numerous occasions during Wednesday's Lower House gender debate. ( ABC News: Rhiana Whitson )

The Government has opposed the amendments since last year, saying the Bill was hijacked by Labor and the Greens, was sloppily drafted, and could have unintended consequences.

The legislation makes gender on birth certificates optional, and removes the requirement for transgender people to have surgery in order to have their gender recognised.

It also allows people aged 16 years or older to apply to change their registered gender without parental approval, and clarifies laws that protect the right of an individual to express their gender without discrimination.

Muted celebrations after bill passes

Transgender activist Martine Delaney welcomed the passing of the bill. ( Supplied )

After the House passed the legislation, there was muted celebration from Greens MPs and transgender advocates seated in the Speaker's Reserve.

Outside the House, Martine Delaney from Transforming Tasmania said it was almost an anti-climactic moment.

"It's been something that's taken so long and it's been such a struggle over the past 12 months, with the Government not at all supporting us, but we've got there," she said.

Ms Delaney said the legislation would save lives, but there were still hurdles getting the wider community to understand.

"That all this will do is make a positive difference to the lives of young trans and gender-diverse people."

Ms Hickey took a moment in the House to express her support for the amended legislation.

"This is indeed an historic occasion," Ms Hickey said.

"I believe wholeheartedly that this Bill removes the discrimination of the transgender community and the only unintended consequence would be that a failure to pass this legislation would result in more psychological damage to the transgender community and their families.

"This is not a win for any particular political party, rather it grants dignity to the transgender community."

Liberal Government won't rule out repeal

The Catholic Church-backed Tasmanian Coalition for Kids, and the Australian Christian Lobby said they hoped the Tasmanian Government would look at repealing the legislation if the opportunity arose.

The coalition's Ben Smith said he believed there would be growing opposition to the changes.

"We have no doubt that when the broader community becomes aware of the negative impact of these changes, that the case for repealing these changes will become overwhelming," Mr Smith said.

In a statement, Premier Will Hodgman did not rule that out.

"Because of the refusal by Labor and the Greens to consider the legal consequences of their amendments, it is highly likely the Parliament will need to fix up problems with the legislation, and [it might mean] repeal of the Labor-Green amendments at a later date," he said.