The bill was passed on Thursday by the lower house and aims to see a 1993 anti-discrimination law extended to crimes motivated by homophobia or transphobia.
A total of 354 politicians voted in favour of the bill and 79 against, La Repubblica reported.
The parliamentary debate was interrupted when dozens of M5S politicians stood in unison and began kissing and hugging each other. Fellow politicians from Beppe Grillo’s party held signs that called for “more rights” for gay people.
Tweeting a photo of the protest (below), MP Federica Daga said “equal rights and dignity without gender. Because a kiss and a hug are not scary”.
Fellow M5S politician Serena Saetti also posted a photo on Twitter (below), with the comment “for civil rights”.
While the bill has now been passed by the lower house, Silvio Berlusconi’s People of Freedom (PdL) party said it would fall in the Senate vote, La Repubblica reported.
The law has faced strong opposition from some members of the PdL, with Renato Brunetta, the party’s leader of the lower house, arguing that it would restrict freedom of speech.
Such an argument has been described as “nonsense” by Vincenzo Branà, president of the Il Cassero LGBT centre in Bologna.
The parliamentary debate on the anti-homophobia bill started in July, but was halted for the summer recess. During the break a 14-year-old boy committed suicide over anti-gay bullying, prompting Laura Boldrini, speaker of the lower house, to call for a new law to tackle homophobia.
Watch a video of the kissing protest: