Lyons Labor  MHA and Speaker Michael Polley and Franklin Liberal MHA Jacquie Petrusma have already said they will vote against the bill.

Health Minister Michelle O'Byrne released a discussion paper yesterday for a proposed private members' bill to strip abortion from the Criminal Code and allow doctors to terminate a pregnancy without conditions up to 24 weeks.

Abortions after 24 weeks would require the written certification of two doctors that the termination would reduce the risk of physical, psychological or socio-economic harm.

``I am bringing the matter on as a private members' bill in order to ensure all members, including those in cabinet, are completely free to vote according to their conscience,'' Ms O'Byrne said.

She said the proposed legislation was modelled on a 2008 Victorian reform and would improve access to abortion in Tasmania by removing the risk of criminal sanctions for doctors and women.

Abortion is allowed under exemptions made to the Criminal Code in 2002, if two doctors certify that continuing the pregnancy poses a medical or psychological risk to the woman.

It is a service mainly provided by two fly-in doctors at day clinics, which are not equipped to terminate a pregnancy after 12 weeks.  

Ms O'Byrne said the debate over a woman's choice had been won in Tasmania in 2001, but access remained restricted.

``We believed in Tasmania that we had put in place laws that would give women access to legal, safe terminations,'' she said.

``It has been shown that that does not exist.''

Ms Petrusma said she was concerned the 24-week window would mean people chose to abandon pregnancies because they did not want a child with a disability, or a child of a certain sex.

``When we look at the genetic testing, are we saying that a person with genetic disabilities has less value than a child without genetic disabilities, and what disabilities are we going to say mean a life has less value?'' she said.

Ms Petrusma said babies born at 24 weeks could be viable, and it did not make sense to fight to save the lives of some while others were discarded.

``Hypothetically, for example, if my mother had had an abortion with me, then I wouldn't of been here, and I would not have had my four children, but then my eldest daughter would not have had her two children . ?. ?. that's seven lives,'' she said.

``I would never condemn any woman who has had an abortion, but we do need to make sure that other options are presented.''

Ms O'Byrne said the 24-week period was tested by the Victorian Law Reform Commission in 2008 and a British parliamentary committee in 2007.

``I think that most members of both houses will look at it in the light of modernising the legislation to fit what Tasmanian women who can afford to go to Victoria are accessing and what most Tasmanians believed we achieved earlier this century,'' she said.

Opposition health spokesman Jeremy Rockliff said the proposed law change was a distraction from other issues facing Tasmania.