The revelation that lawmakers for the Left Party are under observation by the German intelligence service has triggered a debate about the agency's powers. The country's highest court is expected to provide much-needed clarification this year. At what point should spies be allowed snoop on elected representatives? This article was written by SPIEGEL journalists.

Klaus Ernst of Germany's Left Party came face to face with his own insignificance last week. At his party's New Year's reception in Berlin, while sitting in a corner eating meatballs, the party's co-chairman cracked a joke. "If I'm not on the list," he said, "it'll damage my reputation." He even had a button pinned to his suit: "Am LEFT. Please observe."

But his wish wasn't granted -- Ernst's name is not on the list of 27 Left Party politicians under observation by the Federal Office for the Protection of the Constitution (BfV), Germany's domestic intelligence agency. The joke was on Ernst, in fact: one of the agency's criteria for selecting MPs (Members of Parliament) that warrant observation is whether they play a "leading role in the party."

Ever since Spiegel revealed last week how comprehensively the agency is monitoring Left Party MPs, there's a need for clarification: who should be categorized as an enemy of the constitution these days, and who as a friend? Can a member of parliament be an enemy of the constitution? Should the executive branch of the government be allowed to monitor elected representatives of the people -- when really it should be the other way around?

Now, adding fuel to the debate is a further accusation that the BfV kept tabs on Left Party Parliament members not just by analyzing harmless, publicly accessible sources such as newspaper articles -- as it claims -- but also applied intelligence methods such as using secret informants.