The opposition is drafting amendments to the contentious government bill, which is scheduled to be debated in the ACT Legislative Assembly on Thursday - the final sitting day of this parliamentary term.

In an email seen by The Canberra Times, Mr Coe reiterated that the Liberals were opposed to "harmful conversion practices".

But Mr Coe said the definition of conversion practice as it was drafted in the government's proposed legislation was so broad and unclear that it risked criminalising ordinary Canberrans.

Similar concerns have been expressed by religious groups and now the ACT Law Society, which has argued the legislation does not make it crystal clear under what circumstances someone might be breaking the law.

Under the proposed legislation, people would face fines of up to $24,000 and 12 months' imprisonment for performing a "sexuality or gender identity conversion therapy" on a child or individual with an impaired decision-making ability.

The bill defines conversion therapy as a treatment or practice which was aimed at changing a person's sexuality or gender identity. It does not ban practices related to supporting a person who is undergoing or considering a gender transition.

READ MORE

It would also not prohibit practices which help a person express their "gender identity" or that person's "coping skills, social support or identity exploration and development".

Religious groups believe the definition of conversion practice is too broad, fearing it could lead to people responsible for the care of a child being charged with a criminal offence.

In his email, Mr Coe said parents needed support as their child navigated the challenges of growing up, not the threat of government sanctions.

He said the Liberals' amendments would seek to strengthen religious freedoms, including through protections for parents and teachers.

But he acknowledged the Liberals were powerless to stop the bill passing unchanged into law because Labor and the Greens, which both support the legislation, held the majority in the ACT Legislative Assembly.

The chair of the ACT Law Society's criminal law committee, Michael Kukulies-Smith, said the government's definition of conversion practice was "very broad and unclear".

"It is clear the sort of services they might be intending to cover, but it makes it unclear for people such as schools to know exactly where the line is," Mr Kukulies-Smith said.

"Our concern is that they are including a criminal charge related to this, so the ambiguity in relation to the definition becomes more acute when people are exposed to criminal liability.

"We should be able to easily understand when and if we are engaged in criminal conduct."

Mr Kukulies-Smith, who described conversion therapy as "reprehensible", said extra requirements should be added to make clear when it was a criminal offence, such as if the individual was subject to abuse or coercion.

Chief Minister Andrew Barr said Labor would put forward minor amendments during Thursday's debate, but stressed the changes would not amount to a "watering down" of the legislation.

He said among the changes would be a specific reference to section 14 of the Human Rights Act, which provides for freedom of religion and expression.

Mr Barr, whose office has been consulting with religious groups on the bill in the past week, has repeatedly disputed claims that the interpretation of conversion practice is too broad.

He said there was broad support for gay conversion therapy to be banned in the ACT, even among the groups concerned about the drafting of the bill.