A Palaszczuk Labor government bill to decriminalise abortion is being debated in the Parliament this week, with MPs allowed a conscience vote.

The bill would allow abortion on request up to 22 weeks, with a doctor required to consult with a second doctor to receive approval after that time.

It includes safe access zones of 150 metres around clinics to shield women and staff from protesters, while doctors who conscientiously objected would need to refer women to a medical practitioner who would perform the procedure.

As the debate wrapped-up on Tuesday night, 20 Labor MPs and Greens MP Michael Berkman had indicated they would support the bill, while 15 LNP MPs appeared likely to vote against it.

The three Katter's Australian Party MPs were expected to oppose the bill, while the intentions of three LNP members were unclear.

Health committee deputy chair Mark McArdle, the LNP member for Caloundra, was expected to move amendments, including lowering the gestation limit from 22 weeks to 16.

But Mr Miles said choosing 16 weeks could roll back rights Queensland women have under the common law, while describing the current laws as "archaic, cruel and degrading".

"If accepted, the amendment ... would deliver some of the most restrictive abortion laws in the country," he said.

Queensland and New South Wales are the only two jurisdictions in Australia where abortion remains in the Criminal Code.

Mr Miles about 99 per cent of terminations happened well before 20 weeks, while terminations after 22 weeks usually involved complex medical circumstances, such as delayed diagnosis of foetal abnormalities or serious and complex maternal illness.

"These kinds of severe foetal abnormalities are often diagnosed around 20 weeks," he said.

"If we were to set a term limit below 22 weeks we would deny a woman, especially a regional woman, the chance to properly consider her options after the 20-week scan.

"We would be making a law to make her stay pregnant for another 20 odd weeks knowing the fetus will not live."

Mr Miles said clinical guidelines recommended counselling, but making it mandatory would imply there was something inherently traumatic about terminations.

He said the bill repealed sections of the law that were written before women could vote.

"That sits alongside offences such as being gay, defaming a foreign prince, challenging someone to a duel or helping pirates," he said.

Mr Miles said he spent some time in a Marie Stopes clinic and heard stories from staff about how protesters hounded them from their cars, yelled abuse, waved props in their faces and took their photos without permission.

He said women were scared away from visiting the clinic for other services, such as STI check-ups and contraception.

Mr Miles said the bill would not increase late-term abortions, lead to sex-selective abortions, allow women to terminate pregnancies "up until birth" and women would not start using abortion as their preferred method of contraception.

However, LNP deputy leader Tim Mander described Labor's laws as "nothing short of legal killing".

"The fetus in a womb is a baby," Mr Mander, a former CEO of the Scripture Union Queensland, said.

"It is wrong in my opinion to allow a perfectly healthy baby to be killed on demand up to 22 weeks' gestation.

"Our society is better than this and I ask each and every member to search their conscience and remember that your vote will be recorded in the annals of Queensland's history."

LNP leader Deb Frecklington said she did not believe abortion should be available on demand, especially up to 22 weeks, but she was not opposed to some changes, including extra provisions for counselling.

Shadow Attorney-General David Janetzki said he would be opposing the bill, which he criticised for shutting down freedom of speech.

Many MPs became emotional, including Labor member for Pine Rivers Nikki Boyd, who said she went through a miscarriage the last time the issue was debated in 2016 and was now pregnant.

Ms Boyd said the "foul vitriol" which had been sent to her office on the issue had strengthened her resolve for reform.

The debate continues on Wednesday.