Interior Minister Hans-Peter Friedrich's appearance in front of the Bundestag's supervisory panel for the country's intelligence services on Tuesday failed to satisfy the opposition parliamentarians on the committee.
Speaking just days after returning from Washington, where he met with senior US intelligence officials, Friedrich defended the need for intelligence services to conduct surveillance activities as a means of protecting the country from terrorist attacks.
He also repeated a statement made in Washington a couple of days ago, in which he said intelligence collected by the National Security Agency (NSA) had prevented dozens of attacks, including some in Germany. He also said such activities could only be effective when German intelligence services worked together with agencies in Europe and elsewhere.
At the same time he echoed the chancellor's statement made on the weekend, in which she called for stricter privacy protection rules at an international level. Friedrich said he would push for a "digital charter of basic rights" at an upcoming meeting of European Union interior and justice ministers.
The opposition, though, said they felt little the wiser after the interior minister's appearance.
The Social Democrats' parliamentary floor leader, Thomas Oppermann, called on Chancellor Angela Merkel to get personally involved in the case.
"The chancellor needs to personally stand up for the citizens and protect their basic rights," said Oppermann, who is also the chairman of the supervisory panel. "The chancellor needs to exert more pressure towards clarification – we need concrete facts."
However, it still isn't clear whether the committee will call Chancellor Merkel to appear at a future meeting. At its Tuesday meeting, the panel agreed to put that decision off until a later meeting, which could come early next month.
A Left party member of the committee criticized Friedrich for calling on Germans to be more careful about the information they put online.
"Taking care about one's personal information is without a doubt important," Steffen Bockhahn said. "Giving the impression that that better secured data would discourage intelligence services so much that they would cease to conduct surveillance is an attempt to take people for fools."
Chancellor Merkel's conservative coalition has been under fire since former NSA subcontractor and CIA employee Edward Snowden alleged in recent media interviews that a US surveillance program known as "Prism" intercepted information from EU states, including Germany.
Snowden has been on the run since leaking information about US snooping on Americans' phone records and Internet activities to the British daily "The Guardian" and the "Washington Post" several weeks ago.
The controversy comes just weeks before Germans are to go to the polls in a federal election on September 22. Recent opinion polls give Merkel's Christian Democrats more than 40 percent support, higher than that of any other party.
pfd/tj (Reuters, dpa, AFP)