Norway's parliament on Wednesday adopted a new marriage law that allows homosexuals to marry and adopt children and permits lesbians to be artificially inseminated.
After a heated debate, the members of parliament adopted the text by a vote of 84 to 41.
The three centre-left coalition parties in power and two opposition parties, the Conservatives and the Liberals, voted largely in favour of the law, while the Christian Democrats and the far-right Progress Party voted against it.
Norway thus became the sixth country in the world to grant homosexuals the right to marry on an equal footing with heterosexuals, according to Norwegian television TV2.
"This decision is of an importance comparable to universal suffrage and our law on parity," Labour Party rapporteur Gunn Karin Gjul said during the debate.
The most controversial part of the law is that which gives lesbians the right to be artificially inseminated. The sperm donor must be identified so that the child can seek out his or her biological father at the age of 18.
"We are now creating a system where the father is reduced to a sperm sample," lamented Ulf Erik Knudsen, a member of the far-right.
Outside the parliament, a handful of opponents protested with posters reading "Have fathers become superfluous?" and "Parliament has no mandate to change the laws of nature."
Among other things, the new legislation replaces a so-called "partnership law" adopted in 1993 which gave Norwegian homosexuals the right to civil unions.
Health care workers who do not want to perform artificial inseminations on lesbians because of their personal convictions will not be under any obligation to carry out the procedure.
The new law is expected to enter into force at the end of this year or early next year.
Homosexuality was illegal until 1972 in Norway, a country which has since become one of the most liberal in the world in the field.