The French Socialist group in the European Parliament, backed by the Greens, called for the suspension of the trade negotiations and the establishment of a Parliamentary committee to investigate the allegations.
"Before starting negotiations on a future trade agreement (TTIP) with the US, we need a debate about the infringement of international law by Prism and Tempora," said Rebecca Harms, co-chair of the Greens political group, using the codenames for the US surveillance operations.
“Maintaining control of our personal data, our lives, should be a fundamental right,” the French Socialists said in a statement. “The Socialists are at the forefront of this fight. A temporary committee of inquiry, by going to the bottom of this scandal, will allow us to make proposals to defend our freedoms.”
"The surveillance to which European citizens and the European institutions have been the object is unacceptable for a democratic state," the French MEPs said.
Belgian MEP Guy Verhofstadt, leader of the Liberals and Democrats (ALDE) in the European Parliament, called for suspending parts of the trade talks related to data transfers until a parliamentary investigation sheds full light on the allegations.
"I cannot see how a crucial trade and investment partnership can be concluded as long as this spectre of spying hangs over us," he said in a statement, calling for a parliamentary inquiry into the matter.
“Expressing 'concern', is not sufficient,” Verhofstadt added. “We are not only concerned, we are angry. We need a full explanation, not just an apology. We should suspend negotiations on data transfer, retention and protection until the American authorities do so."
German magazine Der Spiegel reported on Saturday (29 June) that the National Security Agency bugged EU offices and gained access to EU internal computer networks, the latest revelation of alleged US spying that has prompted outrage from EU politicians.
The magazine followed up on Sunday with a report that the US agency taps half a billion phone calls, emails and text messages in Germany in a typical month, much more than any other European peer and similar to the data tapped in China or Iraq.
"Partners do not spy on each other," the European commissioner for justice and fundamental rights, Viviane Reding, said at a public event in Luxembourg on Sunday.
"We cannot negotiate over a big transatlantic market if there is the slightest doubt that our partners are carrying out spying activities on the offices of our negotiators," Reding said in comments passed on to reporters by her spokeswoman.
Reactions were outraged in Germany, which was described by the NSA as a “third-class” partner in the leaked documents.
"If the media reports are correct, this brings to memory actions among enemies during the Cold War. It goes beyond any imagination that our friends in the United States view the Europeans as enemies," German Justice Minister Sabine Leutheusser-Schnarrenberger said.
Germany's federal prosecutor's office, which has authority in matters of national security, said it was looking into whether or not it should start an investigation. Criminal charges are expected to be filed, spokeswoman Frauke Köhler told Reuters.
"If it is true that EU representations in Brussels and Washington were indeed tapped by the American secret service, it can hardly be explained with the argument of fighting terrorism," she said in a statement.