Swiss voters overwhelmingly supported the move to open civil marriages and the right to adopt children to same-sex couples after the country voted on Sunday.
According to official results, the bill was approved by 64.1% of voters, winning a majority in all 26 Swiss states, aligning Switzerland with most other Western European countries.
In preparation for the referendum, church groups and other conservative voices opposed change, arguing that it would undermine the traditional notion of the family.
A law already endorsed by all major political parties except the Swiss government and the People’s Party was passed by parliament in December.
However, it was subsequently challenged by activists who had gathered enough support to enforce a national referendum under the Swiss direct democracy system.
The amendment will allow homosexual couples to marry and adopt unrelated children. Married lesbian couples are also allowed to give birth through sperm donation, but are now only an option for heterosexual married couples.
It also makes it easier for Swiss foreign spouses to obtain citizenship.
Marriage with Antonia Housewith, a member of the National Committee, said referendum supporters would celebrate Sunday in Bern, the capital of Switzerland.
“We are very happy and relieved,” she said.
Amnesty International, a human rights group, said opening a civil marriage to homosexual couples is a “milestone of equality.”
But right-wing Swiss People’s Party politician and opponent of the bill, Monica Luiger, said the consequences would hurt her family.
“It wasn’t about love and emotions, it was about the welfare of the children. Here the children and fathers are the losers,” she said.
In another referendum, 66% of Swiss voters appeared to reject the proposal to introduce taxes on dividends, stocks and profits from rent, despite pushes from the young left-wing Socialist Party.