The yet to be implemented law banning discredited “gay cure” therapy in the state of California has been challenged by a Christian legal group, which said it violates privacy, and freedom of speech.

In September, campaigners and medical professionals welcomed California Governor Jerry Brown’s decision to ban teenagers from accessing discredited treatments that seek to reject an LGBT identity.

Lawyers speaking on behalf of the National Association for Research and Therapy of Homosexuality, and the American Association of Christian Counsellors, as well as individuals suing over the issue, spoke in a Sacramento court on Friday, seeking to halt the new law from being brought in.

Attorney, Matthew Staver, the dean of the evangelical Liberty University law school, told the court that the group were seeking an injunction to stop the pending new law from coming into practice. He said:

“What we have here is the state coming into the doctor-patient, client-counselor relationship and saying that you can only present one viewpoint.”

He went on to argue that the new law would violate rights to free speech and freedom of religion, as per the US Constitution. Lawyers for the plaintiffs also said it would deny the right of parents to choose how to raise their children.

Lawyers representing Equality California, a sponsor of the bill, were also present on Friday, as well as attorneys for the state, who argued that the fact that harm is caused to people who undergo the treatments is backed up by substantial evidence.

When the bill was passed, the Human Rights Campaign released a statement saying: “We’re grateful to Governor Brown for standing with California’s children.

“LGBT youth will now be protected from a practice that has not only been debunked as junk science, but has been proven to have drastically negative effects on their well-being”.

When the law, signed in by Governor Brown, comes into effect on 1 January 2013, California will become the first to outlaw the practice for people under the age of 18 in America.

Governor Brown said in a statement that gay “conversion therapy” had “no basis in science or medicine,” and that it would be “relegated to the dustbin of quackery”.