A total ban on so-called conversion therapy has "serious harmful implications" for people living with unwanted same-sex attraction or gender identity, a coalition has said.

The warning comes from the International Federation for Therapeutic and Counselling Choice (IFTCC) in a submission to the government's consultation on a planned conversion therapy ban.

"The characterization of all change-allowing therapy as harmful stigmatizes and puts at risk ethical therapy that uses mainstream therapy methods and has been demonstrated to be helpful and effective for many," the IFTCC said.

The federation takes issue with the term 'conversion therapy', saying that this "confuses" unethical practices like 'aversion' therapies and coercive methods "with standard, voluntary psychotherapeutic and counselling approaches".

The submission says that such unethical methods have already been out of use in professional counselling circles for decades and that trying to ban therapy around same-sex attraction and gender identity will have the consequence of prohibiting "much needed conventional therapy".

This, it says, includes therapy dealing with a range of behaviours or feelings beyond the scope of same-sex attraction or gender identity.

"This is because it is next to impossible for a therapist to completely separate therapy that could lead to a change in a person's same-sex attraction feelings or confused identity feelings, from therapy for related behavior, as attractions or feelings and behaviors are inextricably linked," the submission reads.

Further down, the document says a ban represents "a violation of the free speech of therapists", and will "diminish hope" for individuals struggling with unwanted attractions or identities, especially those who do so because of their religious beliefs.

The coalition says that religious beliefs around same-sex attraction and gender identity "should be respected", and that people should be free to get help if they want it.

"The most serious cases of unwanted same sex sexuality or gender confusion require professional therapy," the submission states.

"If a ban becomes law, adults and children who need therapy will be hard-pressed to find a therapist willing to take the risk of being accused of providing change allowing therapy."

It further adds, "Those who seek therapy, not the state, should choose who gets therapy and for what reasons.

"We urge the state not to support discrimination over who can get help and what help they can get."