Member for Goulburn Wendy Tuckerman has voted against the bill to decriminalise abortion in New South Wales with concerns that an abortion could happen up to 22 weeks without any provisos.
The law currently allows lawful abortions in NSW if a doctor believes the woman's physical or mental health is in serious danger by continuing the pregnancy.
Medical abortions can take place up to nine weeks and surgical abortions are usually performed between seven and 12 weeks' gestation.
"This bill allows abortions to occur very late in pregnancy and in circumstances without a medical need or the provisos that currently exists," Mrs Tuckerman said.
"At 22 weeks, that's a five-and-a-half-month old foetus."
The MP said she was a pro-choice advocate and was in favour of removing abortion from the Crimes Act 1900 but felt that by removing the link to this legislation, it reduced the prosecution for doctors who did the wrong thing.
"If a doctor didn't operate within the terms of the legislation the only ramification would be from the medical services board; it wouldn't be a crime. I find that appalling."
Mrs Tuckerman described the bill as "over-reaching".
"From the outset, it was quite clear to me the bill was going above and beyond what is accepted under common law in the state," she said.
Mrs Tuckerman said she could have supported the bill if she had longer to consult with her constituents and fellow parliamentarians about the legislative framework.
"From my point of view, you're looking at a 100-year-old piece of legislation and if you want to change it you need to get it right," she said.
The Reproductive Health Care Reform Bill 2019 was introduced on August 1 and the debate began in NSW Parliament on August 6.
As a first-term parliamentarian, Mrs Tuckerman said it was a difficult decision to make.
"It was very early in the term to be faced with a conscience vote of this magnitude but hopefully I've done due diligence to the whole debate," she said.
"You're never going to please everyone in politics, no matter which side of the fence you're on, but it's about listening to constituents and with a conscience vote it comes down to yourself; you've got to be able to sleep at night."
She said her office received more than 600 calls, plus correspondence, with the majority of constituents against the bill.
"The complex views raised by constituents made my deliberations on this matter difficult," she said.
"I have given the bill considerable thought, leaning on my life and career experiences, and most importantly I have listened to the people I represent to inform my vote."
Despite 31 MPs voting against the Reproductive Health Care Reform Bill 2019, it passed the State Parliament's Lower House on Thursday night with 59 in favour. The debate went well into the night.
The bill will now be sent to the upper house for consideration.