Almost 66 percent of those who voted in the referendum in the new European Union member endorsed the initiative, launched by the Catholic group "In the Name of the Family", according to preliminary results on Sunday night. Turnout was 37 percent.

The group had gathered over 740,000 signatures in support of the referendum, forcing parliament to call the vote.

The Social Democrat-led government disagreed with the referendum's demand, but the outcome was no surprise in a morally conservative country where 90 percent of the population of 4.4 million say they are Catholic.