BERLIN, July 12 (Xinhua) -- Katarina Barley, lead candidate for Germany's Social Democratic Party (SPD) during the European elections, has said that her party will vote against Ursula von der Leyen as next president of the European Commission, local media reported on Friday.

"As things stand now, the SPD delegates cannot agree with the applicant," said Barley, who is currently a member of the European Parliament (EP), in an interview with the German newspaper Passauer Neue Presse.

Current German Defense Minister von der Leyen did not present herself in the European election as a lead candidate and thus she did not give voters the opportunity to learn about her "European political ideas" as a candidate for president of the Commission, according to Barley.

Last week, von der Leyen was nominated by the leaders of the EU member states to replace the current President of the European Commission, Jean-Claude Juncker. Von der Leyen did not run as a lead candidate for her party, the Christian Democratic Union.

"We, German Social Democrats, remain committed to the lead candidate principle," Barley stressed.

Von der Leyen failed to convince Barley with her policy plans for the EU as "much has remained vague" after her two-hour grilling by the Progressive Alliance of Socialists and Democrats (S&D) group in the European Parliament on Wednesday, according to Barley.

Questioned about the rule of law, von der Leyen answered that this would be a "legal and not a political question", said Barley.

In von der Leyen's view, Poland's judiciary reform, for example, would "solely be a matter for the Court of Justice of the European Union", Barley recalled. The German Social Democrats hold a "fundamentally different view" on this, and for them the rule of law would be an "eminently political" issue, said Barley.

The European Parliament is scheduled to elect the new president of the European Commission next Tuesday.

Differences between von der Leyen and the Social Democrats have intensified after an S&D member of parliament circulated a paper filled with political and personal accusations against von der Leyen during the European Parliament hearing on Wednesday.

The title of the paper was "Why Ursula von der Leyen is an inadequate and unsuitable candidate".

In the paper, the Social Democrats alleged, among other things, that von der Leyen had used an excessive number of consultants in the German Defense Ministry, and cited the "exploding costs" in the renovation of the German Navy's three-masted training ship Gorch Fock.

The leader of the German SPD party, Thorsten Schaefer-Guembel, distanced himself from the report on Thursday. He told the German newspaper FAZ that his party's leadership had not been informed about the "compilation of public press criticism" of von der Leyen.