Sweden’s ruling Social Democratic Party (SAP) granted support for the country’s NATO membership application, marking a fundamental change in the party’s position as a staunch opponent of military alignment.

The ruling SAP supported applying for NATO membership on Sunday, Xinhua news agency reported.

“We Social Democrats believe that the best thing for Sweden’s security is that we join NATO,” Sweden’s Prime Minister Magdalena Andersson, also a leader of SAP, told a press conference in Stockholm after the party’s extraordinary meeting.

The Swedish Social Democrats’ change of its stance toward NATO is regarded as historic, as the party’s politics clearly said “the military freedom of alliance is a foundation in Sweden’s security policy”.

It has also added that “Sweden’s partnership with NATO contributes to increased security in our immediate area, while a NATO membership would have the opposite effect”.

Andersson quoted the change of security situation to justify the party’s decision, which paved the way for the country’s widely-speculated NATO membership application early next week.

“The military freedom of alliance has served us well, but it will not serve us well in the future,” the Prime Minister said, pointing to the changed security situation, with the Ukraine crisis in particular.

Andersson emphasised the “invaluable” cooperation with neighbouring Finland, which made its official decision to apply for NATO membership earlier on Sunday.

“If Sweden were to become the only country in the Baltic Sea region outside NATO, we would end up in a vulnerable position,” she said, adding that Sweden must apply together with Finland and “as soon as possible”.

However, the SAP’s decision incurred fierce criticism in Sweden.

“Today’s message is a big disappointment,” said Agnes Hellstrom, Chairman of the Swedish Peace and Arbitration Society, adding that “the decision is sad and hasty and leads Sweden and the world in the wrong direction”.

“Through this decision, Sweden contributes to making the world more militarised and polarised. A NATO membership does not make Sweden or the world more secure or democratic — rather the opposite,” the Society wrote in a statement.

Swedish Social Democratic Youth Union (SSU) also voiced their criticism of the decision.

“Young people are the ones who are most critical of a NATO membership and that is understandable. They are young people who risk being sent to war to defend other countries… Sweden must continue to be a voice and a force for peace,” the Union’s Chairman, Lisa Nabo said in a statement.

“SSU now demands the government that for future generations they guarantee a Sweden free of nuclear weapons, a nuclear-weapon-free zone across the Nordic region and that foreign military bases are never established in Sweden,” the statement added.