The decision was taken by a clear majority: 53 members voted in favor, five voted against and two abstained.
The party thus changes its official attitude towards NATO.
The party justifies the shift with the changed security situation in Europe.
Wants Sweden to follow
Already in the keynote address given at noon, Prime Minister Sanna Marin said that the party board unanimously supports NATO membership, and she once again emphasized the importance of Sweden and Finland making the same decision.
- Would NATO membership in this changed situation increase Finland's security?
Does Finnish NATO membership strengthen Europe's security?
The answer is that it is increasing.
The answer is that it strengthens, said Marin.
The chairman of the Riksdag group, Antti Lindtman, said that Finland could not take the slightest risk of being left alone with Russia.
Tomorrow, the official decision by the top government on a Finnish NATO membership is expected.
It will be debated in the Riksdag on Monday, after which the Riksdag will vote on the issue.