Making its stance against same-sex marriage clear, Slovakia’s parliament passed an amendment to its constitution, defining marriage as a union between man and woman. The amendment, drafted by leftist Prime Minister Robert Fico's Smer-Social Democraty party and the opposition Christian Democrats, was backed by 102 lawmakers while 18 voted against it.
The amendment required a two-thirds majority in the 150-member parliament.
"The marriage amendment will not bring about any drastic changes, it only seals in the constitution what is already defined by law," said Fico, whose Smer is a member of the traditionally liberal Party of European Socialists group in the European Parliament.
The European Union's newest member Croatia outlawed same-sex marriage in a referendum last year, triggering a similar constitutional amendment, but swiftly passed a civil union law for same-sex couples.
No form of same-sex civil union is legal in Slovakia, where more than 70 percent of the population of 5.4 million is Christian, according to a 2011 census.
But a 2012 opinion poll showed that 47 percent of Slovaks supported civil unions for same-sex couples while 38 percent were opposed.
"You don't make marriage more attractive by banning all the alternatives," Martin Macko, head of the LGBTI Initiative "Inakost" added.
Same-sex marriage is legal in a handful of the 27 other EU states including Britain and France, while civil unions are recognised by the Czech Republic, Germany and others.