German Finance Minister Wolfgang Schäuble (pictured above) caused a stir on Friday when he compared a rival party's candidate for chancellor to US President Donald Trump.

Schäuble, who is a member of Chancellor Angela Merkel's Christian Democratic Union (CDU), called Social Democrat (SPD) Marin Schulz "Trump, almost word-for-word" in an interview with "Der Spiegel." He also accused the former president of the European Parliament of trying to ride a similar wave of populism that put the real estate mogul in the White House.

The SPD's poll numbers have been slowly declining for a decade. The party hopes Schulz will change that trend

Trading Trump barbs

In response, SPD politicians accused Schäuble of "irrelevant" and "hysterical" criticism of their candidate, adding that the statement must have come from a panic in the CDU as Schulz's popularity among German voters increases.

"My advice to Mr. Schäuble is that he should say fewer things that show that he knows little about the reality of his fellow citizens," SPD deputy leader Ralf Stegner told the Funke Media Group of regional newspapers.

For the past four years, the CDU and SPD have been ruling together in a grand coalition after 2013 election results shut out the CDU's preferred coalition partner, the Free Democrats (FDP). In this year's federal election, however, the SPD wants to come back from its sinking popularity and loss of profile.

To that end, it eschewed putting forth party leader and current Foreign Minister Sigmar Gabriel as its candidate. Instead, it chose longtime European-level politician Schulz, who is considered far more likeable because of his working-class background and experience at fomenting grassroots support from his years as a politician at the municipal level.

'Make Europe Great Again'

"If Schulz allows his supporters to use the slogan 'Make Europe Great Again,' then he is Trump almost word-for-word," said Schäuble, referencing the use of the slogan and the hashtag #MEGA by a small group of Schulz supporters on the website Reddit.

Schäuble continued, "in a time when populism is seducing people the world over, politicians should not speak like Mr. Schulz. If he wants to fight populism, as he claims, he should take note of these facts."

Schulz has himself expressed his distaste for the US president's bombastic rhetoric, calling Trump "dangerous to democracy" and accusing him of "playing with the security of the Western world."

In the same interview with "Spiegel," Schäuble also scoffed at what he perceived as the SPD trying to promote Schulz as a political underdog. "The man has sat in the European parliament for decades, most recently as its president," Schäuble said. "If that's not part of the establishment, what is?"