Swedish Social Democrats, an opposition force in the current government, have come first at the general elections.

Leader Stefan Lofven vowed not to allow far-right Sweden Democrats in the next cabinet, after his 43.7% (partial results as of early Monday) were likely to prevent his party from going it alone.

Center-right Moderate Party of PM Fredrik Reinfeldt trailed behind with 39.3 percent (compared to his 49.3% in 2010, when he was reelected), while Sweden Democrats were third, at 13%.

Reinfeldt is to vacate the post on Monday and also to resign as his party's leader.

Lofven, for his part, pledged to fight Sweden's economic and social issues, with unemployment and Swedish children dropping down in school results compared to other EU states seen as major problems prompting voters to cast ballots in his favor.

The Social Democrats ran in the general poll together with the Greens and also with the Left Party, a socialist-feminist organization.

Their coalition is expected to have some 159 seats in the 349-strong Parliament, failing to form a majority, but has fulfilled its aim to get more than 35 percent set after 2010's devastating 30.66 percent, Der Spiegel reports.

The Swedish Social Democratic Party (SAP) has dominated Sweden's polifical life since 1920, with Reinfeldt's tenure (from 2006) having been their biggest stay out of power.

Swden Democrats, on the other hand, have nearly doubled their support since 2010.