The Greek parliament on Thursday voted in favor of a bill to allow same-sex couples to marry.

It makes Greece the first Orthodox Christian country to legalize same-sex civil marriage.

The bill was approved by a cross-party majority of 176 lawmakers in the 300-seat parliament.

"This is a historic moment," Stella Belia, the head of same-sex parents group Rainbow Families, told Reuters. "This is a day of joy."

Prime Minister Kyriakos Mitsotakis called the outcome "a milestone for human rights" and noted that Greece was the 16th country in the European Union to legislate marriage equality.

The bill also grants adoption rights to same sex couples.

"Both parents of same-sex couples do not yet have the same legal opportunities to provide their children with what they need," Prime Minister Kyriakos Mitsotakis said ahead of the vote on Thursday night.

"To be able to pick them up from school, to be able to travel, to go to the doctor, or take them to the hospital. ... That is what we are fixing."

However, the law does not allow parenthood through surrogacy for male couples — an option which is available to women who cannot have children for health reasons.

LGBTQ+ activists and supporters celebrated the outcome on Thursday night Deutsche Welle

Opinion polls suggest that most Greeks support the reforms by a narrow margin.

The bill was supported by many lawmakers from Mitsotakis' center-right New Democracy party along with four left-wing parties, including the main opposition party Syriza.

"This law doesn't solve every problem, but it is a beginning," said Spiros Bibilas, an openly gay lawmaker from the small left-wing Passage to Freedom party.

However, three small far-right parties as well as the Stalinist-rooted Communist Party of Greece (KKE) rejected the bill.

The head of the Orthodox Church of Greece, Archbishop Ieronymos, also condemned the law as a "new reality that seeks only to corrupt the homeland's social cohesion."

Outside parliament, opponents of marriage equality held religious icons and prayed while supporters waved rainbow flags.