The Queensland parliamentary committee considering laws to decriminalise abortion has been told parts of the proposed legislation could be unconstitutional.

Legal experts have warned parts of proposed laws to decriminalise abortion in Queensland could be found unconstitutional.

A state parliamentary committee conducted a public hearing in Brisbane on Wednesday, with a variety of stakeholders giving their views on the proposed laws.

The changes would see abortion taken out of the criminal code and made a health issue, with the procedure available to women up to 22 weeks' gestation.

After that point a woman would require two separate doctors to approve the measure.

It also would establish "safe zones" around abortion clinics which would prevent pro-life demonstrators from harassing women and staff.

However constitutional law expert Professor Nicholas Aroney told the committee that aspect of the laws could be unconstitutional, because it hampered the right of the demonstrators to protest.

He warned the High Court had recently moved to a hard line on state laws which infringed on freedom of political communication.

"There's a real risk that the bill as drafted would fail that test," he said, but clarified that if that section of the legislation was struck down by the High Court, the rest of the law could still function.

Queensland Law Society Deputy Chair Rebecca Fogerty said they believed the risk of the safe zones being struck down by the High Court was low.

"Safe Access Zones represent an extremely modest restriction on free speech," Ms Fogerty said.

"Anti-abortion campaigners are free to protest wherever else they like, they just aren't able to protest within 150 metres of a person that is seeking to access an abortion"

Wednesday was the last of three days of public hearings on the proposed laws, with the committee hearing emotional testimony from women who have had late-stage abortions, all advocating for the procedure to be decriminalised.

The committee will report back to the government by October 5, with laws expected to be debated in state parliament later that month.

The Labor government will allow its MPs a free vote, while the LNP opposition is waiting for the committee's report before it decides whether to grant its members a conscience vote.

Queensland and NSW are the only states of Australia that still treat abortion as a crime, with the Queensland laws dating back to 1899.