It is the Finnish government that decides on the application, but broad support in the Riksdag is absolutely crucial.
In the coming weeks, the parties and members of the Riksdag must decide whether Finland should apply for membership or not.
Foreign Minister Pekka Haavisto (The Greens) said in Wednesday's parliamentary debate that if Finland and Sweden apply for membership at the same time, it would facilitate preparedness for possible Russian reactions.
The several-hour debate is the only one that will be held in public - now the political discussions in the Riksdag committee are continuing.
Antti Häkkänen, group chairman of the National Coalition Party, advocates a Finnish membership in the military alliance and now wants to speed up the process.
"The NATO decision must take precedence over all other parliamentary work," he said.
Hear the politicians about Finnish NATO membership in the clip above