"We want a neutral law that says that everyone should be able to marry whoever they want, and how many they want," Katrine Jakobsen Solberg, head of the Progress Party youth wing in the country of Hedmark, said shortly after voting through the proposal at the group's annual meeting.
Solberg told Norway's Dagbladet newspaper that the youth wing would now formally propose the new policy at the Progress Party's national conference in the spring.
"Personally, I have trouble finding arguments against polygamy," she said. "I do not think the government should interfere in peoples' love lives."
Atle Simonsen, a member of the party's central committee, said the party welcomed new ideas from its youth wing, but suggested that this one was unlikely to become official policy.
"From a freedom perspective, one can argue that polygamy should be legal, but we know that most people who live in this way, do not do it voluntarily. Therefore, I think it's a pretty bad idea," he said.