The Victorian government is again trying to reform the birth certificate regime in favour of trans, gender diverse and intersex people.

Trans, gender diverse and intersex Victorians will no longer need to have gender reassignment surgery in order to change the sex on their birth certificate, under proposed new laws.

The state Labor government will on Tuesday introduce a bill to parliament which, if passed, will allow applicants to self-nominate the sex listed on their birth registration as male, female, or any other gender diverse or non-binary descriptor of their own choice.

This alters the current regime that requires an individual to undergo gender reassignment surgery before their birth certificate can be changed.

"The current surgery requirement sends a painful and false message that there is something wrong with being trans, gender diverse or intersex that needs to be 'fixed' - that's why we're removing this cruel and unfair barrier," Attorney-General Jill Hennessy said in a statement.

The reform also recognises some trans and gender diverse people are unable to, or choose not to, undergo such medical procedures.

But Victoria's Registrar of Births, Deaths and Marriages will be able to refuse a descriptor that's obscene or offensive or isn't a recognisable sex descriptor.

Children will also be able to apply to alter the sex on their birth certificate but only with the backing of their parents and a supporting statement from a doctor, registered psychologist or another prescribed person who can confirm ti would be in the child's best interest.

This is the second time the Andrews government has presented the bill to state parliament. Last time, it was voted down.

Opposition Leader Michael O'Brien said the key question was whether a birth certificate reflected the sex of a person at birth or how they identified themselves.

"We don't know if it's going to be exactly the same bill (as last time) or a different bill or slightly different, so we'll see the detail and then we'll make a reasoned decision," he told reporters.

Father Tony Kerin, the Catholic Church's Episcopal Vicar for Life, Marriage and Family, said the church did not "approve or appreciate" the reform.

"When it comes to gender, we stick with the science, we count chromosomes," he told ABC radio.