The survey, carried out by polling institute Novus, showed that 51 percent of Swedes were in favour of joining the military alliance, the first time the pollster has recorded a majority on the issue and up from 45 percent just a week ago.

Russia's invasion of Ukraine has sparked a surge in public support for joining NATO.

Recent polls by other institutes have previously shown a majority in favour of joining, but Novus said it believed public opinion was now being influenced by the NATO debate underway in neighbouring Finland, where the issue is being mulled by MPs following the publication of a security policy white paper last week.

Many analysts have predicted that Finland will ultimately submit a bid in time for a NATO summit in June.

Finnish Prime Minister Sanna Marin visited her Swedish counterpart Magdalena Andersson last week, signalling that the neighbouring countries, which are both NATO partners but officially "non-aligned", are moving in unison.

"Swedish opinion in favour of NATO is increasing because they believe it will be done together with Finland and (people) are then more positive to a Swedish membership," Novus chief executive Torbjorn Sjostrom said in a statement.

If Finland were to join the alliance, 64 percent of Swedes questioned said they were in favour of joining.

Swedish Foreign Minister Ann Linde said Thursday she wanted to speed up the completion of parliament's security policy analysis that is meant to guide MP's discussions.

Linde told broadcaster Sveriges Radio that she wanted it completed by May 13, instead of May 31 as currently planned.

"Finland has already published its analysis and there is strong pressure on us to complete our analysis," Linde said.

Sweden's ruling Social Democrats said last week they would begin an internal debate on whether Sweden should apply for membership.

The party has historically opposed NATO membership. A reversal of that policy would pave the way for a Swedish bid.

According to newspaper Aftonbladet, sources within the Social Democrats said a "marathon meeting" on NATO was scheduled for Friday, the party's "first major discussion" on the issue.