Homosexual relations are punishable by up to 15 years in prison.
The bill has been condemned by rights groups as an “attack on human rights”.
Amendments to the 1988 Anti-Prostitution Act, passed in a session attended by 170 of 329 lawmakers, will make transsexuals face three years in prison.
An earlier draft proposed the death penalty for same-sex relationships, which campaigners called a dangerous escalation.
The new amendments allow courts to hand down sentences of 10 to 15 years in prison for having same-sex relationships, according to a document seen by the AFP news agency.
Even before this bill, homosexuals and transgender people in Iraq often faced attacks and discrimination.
The amendments also set a minimum sentence of seven years in prison for promoting same-sex relationships and one to three years in prison for men who intentionally act like women.
Under the new bill, “biological sex change based on personal desire and inclination” is a crime, and transgender people and doctors who perform sex reassignment surgeries are punishable by up to three years in prison.
Homosexuality is taboo in conservative Iraqi society, but there was previously no law that explicitly penalized same-sex relationships.
Members of Iraq’s LGBTQI+ community have been prosecuted for sodomy or under vague articles of the Iraqi penal code regarding morality and prostitution.
“Iraq has legalized the discrimination and violence that members of the LGBTQI+ community have suffered with impunity for years,” said Razaw Salihy, Amnesty International’s Iraq researcher.
“Amendments for LGBTQI+ rights violate basic human rights and endanger Iraqis who are already persecuted on a daily basis,” Salihy added.
The amendments also ban organizations that promote homosexuality, and “wife swapping” carries a prison sentence of 10 to 15 years.
“The law is a preventive measure to protect the public from such acts,” lawmaker Riyad al-Maliki, who drafted the amendments, told AFP.
He said the adoption of the new amendment was delayed until Iraqi Prime Minister Mohamed Shia al Sudani’s visit to the United States earlier this month.
Given that the United States and the European Union oppose the law, “we didn’t want to influence the visit,” he said.
“This is an internal matter and we do not accept any interference in the affairs of Iraq,” he added.
A 2022 report by Human Rights Watch (HRW) and the NGO IraQueer stated that Iraqis belonging to the LGBTQI+ community were forced into the shadows and were often victims of “kidnapping, rape, torture and murder” with impunity.
Iraqi politicians and social media users are increasingly resorting to anti-LGBTQI+ rhetoric, further fueling fear among community members.
Human rights group HRW’s Iraq researcher Sarah Sanbar said the new law change “is a terrible development and an attack on human rights”.
“Instead of focusing on passing laws that benefit Iraqis, such as domestic violence or child protection, Iraq is choosing to codify discrimination against LGBTQI+ people,” she said.
