Martin Schulz is behind a spike in support for the SPD | Emmanuel Dunand/AFP via Getty | Emmanuel Dunand/AFP via Getty Germany’s center left takes poll lead for first time in decade SPD surge follows pick of former European Parliament president Schulz as its candidate.

Germany’s Christian Democrats (CDU/CSU) have slumped to second place in an opinion poll conducted by the Emnid institute, putting the Social Democrats (SPD) in the top spot for the first time since 2006.

The SPD's climb comes after the party picked the former President of the European Parliament, Martin Schulz, as its candidate for chancellor.

Emnid’s poll of 1,885 voters found that the SPD would get 33 percent of the German vote, while Chancellor Angela Merkel’s CDU and its Bavarian sister party, the Christian Social Union, would get 32 percent.

Schulz's party has gained 12 points in the last four weeks, according to German newspaper Bild am Sonntag.

The SPD's surge in the polls will add more pressure on Merkel, as she seeks her fourth term as chancellor within an uneasy CDU/CSU alliance. Merkel has faced tough criticism from the sister party over the controversial decision to temporarily open Germany’s borders to refugees in 2015.

This is the latest in a series of polls that shows SPD’s rapidly rising popularity among German voters. Emnid’s poll chimes with separate findings by Politbarometer, a long-standing German election poll from German broadcaster ZDF, which showed Friday that 38 percent of voters would like to see Merkel carry on her job as chancellor and that 49 percent preferred Schulz. The ZDF poll found that 71 percent of Germans think that the current chancellor is doing a good job, but want a change in the top job.

German elections are scheduled for September.