Russian lawmakers in the lower house of parliament on Friday voted overwhelmingly in favour of new legislation that would make gender reassignment illegal, further cementing an ultra-conservative, anti-Western drive in society.

"The State Duma banned gender reassignment in Russia. The relevant changes to the legislation, initiated by the Chairman of the State Duma Vyacheslav Volodin and deputies of all factions, were adopted in the final version unanimously," read a statement on the Duma's website.

"This decision will protect our citizens and our children," Volodin said in a separate statement on social media.

The new legislation must first be approved by the upper house of parliament and President Vladimir Putin before entering into force, steps seen as formalities in a country where lawmakers are loyal to the Kremlin.

The Duma statement said that the new legislation will have sweeping consequences for Russian transgender people: "citizens who have already changed gender will be prohibited from adopting children, and their marriages will be annulled."

Since the start of its offensive in Ukraine, Russia has adopted a series of conservative measures, particularly against the LGBTQ community, aiming to clamp down on behaviour authorities consider deviant and Western-influenced.

Russia's FSB security service announced earlier this week it had arrested a transgender rights activist accused of "high treason" for supporting the Ukrainian military.