Ottawa Mayor Jim Watson is asking city council to formally denounce conversion therapy and demand the federal government reintroduce a bill criminalizing the controversial practice.

Conversion therapy attempts to force individuals, in many cases children, to change their sexual orientation, gender identity or expression through counselling or medication. The practice has been condemned by the Canadian Psychological Association as harmful because it can cause anxiety, depression and distress.

Watson, who came out as gay just over one year ago, plans to introduce a notice of motion during Wednesday's council meeting asking his council colleagues to formally denounce the practice "as harmful for individuals and to society by promoting myths and stereotypes about sexual orientation and gender identity."

The motion, which will be debated at the next council meeting in early September, also encourages anyone who has undergone conversion therapy to seek professional help from a number of local resources, and anyone who suspects someone has been kidnapped or forcibly confined to contact Ottawa police.

If passed, Watson will write to the prime minister and attorney general, among other parliamentarians, asking that Bill C-8, which would amend the Criminal Code to outlaw the practice of conversion therapy, be reintroduced "as soon as possible in the upcoming session of Parliament."

Bill C-8 would create new offences including causing a person to undergo conversion therapy against their will, forcing a child to participate, removing a child from Canada to engage in the therapy outside the country, advertising conversion therapy and making a profit from it.

The bill did not proceed through Parliament after its first reading in March. Parliament is currently prorogued until to Sept. 23.

Watson's motion follows an analysis by Anthony Di Monte, the city's general manager of emergency and protective services, who was asked by the mayor to look into whether the city could go ahead and regulate the practice through its own bylaws.

"There is no clear authority for council to prohibit a business outright in Ontario," Di Monte concluded in a memo to the mayor and council on Tuesday.

Di Monte found there are "practical and other impediments" that will make it "quite challenging" for the city to ban conversion therapy on its own.

Through consultations with advocacy groups including Capital Pride and No Conversion Canada, it's clear conversion therapy is often done in secret, and police would be better equipped to investigate it as a criminal matter, he said.

Since the federal government is in the process of banning conversion therapy, municipalities need to be careful with their own laws so that they don't conflict with that legal framework, Di Monte said.

While Canada has not yet banned conversion therapy, the practice is already illegal in Ontario and the City of Calgary, while Manitoba, Nova Scotia and Vancouver have introduced restrictions.