BERLIN — German Chancellor Angela Merkel’s conservatives scored another victory in a regional election, giving the party a boost ahead of the national vote this fall.

On Sunday, Merkel’s Christian Democrats (CDU) won 33 percent of the votes in Schleswig-Holstein, Germany's northernmost state, almost 7 percentage points ahead of their main rival, the center-left Social Democrats (SPD) at 26.2 percent, according to exit polls by infratest dimap, released by public broadcaster ARD on Sunday evening after ballots closed.

The result of the vote — the second of three regional elections this year — could allow the conservatives to push out incumbent SPD state premier Torsten Albig, who has governed since 2012.

“People made a clear decision, the state government ... has been voted out of office,” said the CDU’s regional candidate Daniel Günther after first results were announced.

"It's a bitter day for social democracy," the SPD's Albig told his party faithful.

The Greens won around 13.3 percent of the votes, according to the exit poll, ahead of the liberal Free Democrats (FDP) at 11.5 percent, far-right Alternative for Germany (AfD) at 5.6 percent and the ethnic Danish minority party Südschleswigsche Wählerverband (SSW,) which only exists in Schleswig-Holstein, at 3.5 percent.

"It's a bitter result" — SPD's General Secretary Katarina Barley

During the last election five years ago, Merkel’s CDU got marginally more votes than SPD (30.8 percent versus 30.4 percent) but ended up being pushed into the opposition by the Social Democrats, who formed a coalition with the Greens and the SSW.

This time, however, such a coalition won't be able to secure enough seats to reach the majority necessary to govern.

Depending on the final results, majorities could possibly be formed by the CDU either going into a so-called Jamaica coalition with both the Greens and the FDP; by a grand coalition of the CDU with the SPD as junior partner, or even by the SPD — despite its defeat — partnering up with the Greens and the FDP in a so-called "traffic light coalition."

On the national level in Berlin, Merkel’s CDU and its Bavarian sister party CSU have led a "grand coalition" as the senior partner with the SPD since 2013 and previously between 2005 and 2009.

When Germans go to the polls in September to vote for a new national parliament, the Social Democrats are determined to push Merkel out of office.

Earlier this year, they enjoyed a spike in the polls after declaring that former European Parliament President Martin Schulz would run as SPD's candidate against Merkel.

However, the phenomenon dubbed the “Schulz effect” failed its reality test in the first regional election in March, when Merkel’s conservatives posted an unexpectedly big victory in the small western state of Saarland, winning 40.7 percent of the vote to finish more than 11 percentage points ahead of the SPD.

It led to first speculations about a “declining Schulz effect” — and Sunday’s disappointing result for the SPD in Schleswig-Holstein will throw more cold water on the party's declared goal to become the strongest party in the German parliament in September.

"It's a bitter result," the SPD's General Secretary Katarina Barley told public broadcaster ARD, "We failed to to mobilize [voters]."

The most important election is yet to come

With a population of just 2.8 million — 2.3 million of whom were eligible to vote — agricultural Schleswig-Holstein is primarily a staging ground for the third and most important regional election.

Next weekend, voters in North Rhine-Westphalia go to the ballots. Germany’s most populous state is home to around 18 million people, more than a fifth of the country’s entire population of 81.5 million.

With more than 13 million people eligible to vote, that election is widely considered one of the most important indicators of the national mood ahead of the September election.