Now, politicians in Greece are voting on whether to legalize same-sex marriage. If the vote passes, it would make Greece the first country with a Christian Orthodox majority to do so. The bill was introduced by the country's centre-right Prime Minister, Kyriako Smitsutakis, but about a third of his own MPs are expected to vote against it. That means he needs the support of politicians in the left wing opposition for it to pass. Our correspondent, Mark Loewen, is following the story from Lisbon. He explain how significant this is for Greece.

It's very significant in terms of being the first Orthodox majority country, as you say, Rich, and also the first country in southeast Europe, a region that is surrounded by countries that have not legalized same-sex marriage. The majority of the 15 EU members which do allow it are grouped in the West and North of the European Union, so Greece would become an exception to that. It is a country where many still feel rooted in the country's tradition and religion, and the powerful Orthodox Church has been fiercely against this and has written a letter for prelates to read out in church services earlier this month in which they condemn the move. And that's reflected in views across society. So a recent poll found a very slim majority in favor of the same-sex marriage bill, about 55% or between 53 and 55%. But the Prime Minister feels that this is a time for Greece to catch up with many of its Western European neighbors and to pass a bill that would enshrine marriage equality and allow same-sex couples to adopt children.

Mark, as you mentioned, this is really teetering on the lines here when it comes to public support. Is the Greek Prime Minister gambling his political future on this?

I don't think so because he faces a pretty weak opposition at the moment. The fact that he has felt confident enough to bring in this bill shows shows how stable he feels actually in power. He recently stormed to re-election, a second term. One might think actually the same-sex marriage would be a move that a left-wing government or center-left government might try to introduce But here you have a center-right Prime Minister who feels that now is the time for Greece to, in effect, stand up to the Orthodox Church and pass this. It is a sign of his confidence that he feels ready to tread on the turf of a political move that is more associated with the left wing and to push it through. And that despite the fact that up to 50 MPs of his own, 158 MPs might rebel against him. He feels that he's got the support of opposition parties and is likely to pass in a vote later on tonight.

And we will follow that story here and bring you the latest on that vote when it happens around the world and across the UK. This is BBC News.