The verdict was greeted with cheers from spectators in parliament and dozens gathered on the streets of Athens.

The law grants same-sex couples the right to marry and adopt children and comes after decades of LGBT campaigning for marriage equality in the socially conservative country.

Greece is one of the first Orthodox Christian countries to allow such unions. “This is a historic moment,” said Stella Belia, head of same-sex parents group Rainbow Families.

The bill has been approved by 176 lawmakers in the 300-seat parliament and will become law when published in the government's official gazette.

“This is a very important step for human rights, a very important step for equality and a very important step for Greek society,” said Nikos Nikolaidis, a 40-year-old historian who took part in a protest in support of the bill.

Recent polls show Greeks are divided on the issue. The powerful Orthodox Church, which believes homosexuality is a sin, has strongly opposed same-sex marriage, while many in the LGBT community believe the bill does not go far enough.

Elliniki Lysi, one of three far-right parties represented in parliament, called the bill “anti-Christian” and said it harmed the national interest.

"Of course I would vote against it. Same-sex marriage... is not a human right," said former Prime Minister Antonis Samaras, a New Democracy lawmaker.

LGBT groups protest outside the Greek Parliament. A banner reads: "No retreat from true equality".

“I am very proud as a Greek citizen because Greece is one of the most progressive countries today,” said Ermina Papadima, a member of the Greek Association for Support of Transgender People. “I think the mindset will change… We have to wait, but I think the law will help solve the problem.”

Campaigners have been pushing for change for decades, often against the tide of the Church and right-wing politicians. In 2008, a lesbian couple and a gay couple defied the law and married on the small island of Tilos, but their wedding was later annulled by the Supreme Court.

Mai Anh (according to Reuters)