German Chancellor Angela Merkel's dealings with the Obama administration on key trans-Atlantic issues, including electronic surveillance, look set to become an increasingly decisive issue for voters before Sept. 22 elections.

So far Merkel, elected Nov. 22, 2005, has appeared comfortable, widely regarded as the world's second most influential person after the U.S. president. But Merkel is increasingly under fire over her alleged reticence and unwillingness to talk about how much she knows of the alleged U.S. intelligence gathering in Europe.

With eight weeks to go before the polls Merkel has embarked on an 18-day holiday seen by analysts as confident posturing by a chancellor who is sure of winning a new term.

Her vacation has also removed Merkel from the center of a storm brewing in the German political establishment over what some see as a gathering unease in relations between Berlin and Washington. Popular discomfort over charges Germany has been both a victim and a collaborator in U.S.-led electronic surveillance continues to boil over in the news media. Press commentaries and the intensity of criticism of the United States usually reflects partisan bias of the news organization, but more and more of it is being published in print, on air and on the Internet.

Der Spiegel, the largest news magazine, is more outspoken in its criticism than before and recently added to surveillance what it saw as two other German gripes: the continued operation of the prison at Guantanamo Bay, Cuba, and U.S. drone strikes.

Recent opinion polls suggest Merkel's center-right coalition would have a narrow lead in September over a center-left alliance bringing together the Social Democratic Party and the Greens. A more skeptical analysis of public mood in Germany over the electronic surveillance controversy maintains Merkel isn't doing enough to secure U.S. explanations on the surveillance issue or to fix the eurozone.

In contrast, SPD leaders recently indicated, an alliance with the Greens would give SPD and the Greens together enough clout to call the shots not only on future talks with Washington on the surveillance issue but also on fixing the debt-bound eurozone.

SPD leader Sigmar Gabriel told a Green Party congress, "There are only two parties in Germany that can tame the financial markets, and that's you and us." Gabriel's assertion left open the possibility the SPD opposition in the coming weeks would be asking Merkel's administration tough questions on ties with the United States.

SPD pronouncements suggest the party is keen to see a split within Merkel's coalition on key issues confronting Germany, from national security and environment to the wider diplomatic issues of German-U.S. ties.

Merkel's junior partner Free Democrats in recent comments indicated the party differs with Merkel and her aides on eurozone economic priorities. With eyes on a future coalition with different partners, Merkel aides are also wooing the Greens to deny SPD an opportunity to forge an anti-Merkel alliance.

Gabriel, for his part, has set sights on building a closer link with the Greens as a way of defeating Merkel and forming a strong left-wing alliance on a largely left-wing platform.

"The scale of this scandal is so large that nobody other than the chancellor personally needs to ensure that basic rights are protected in Germany," Gabriel told Spiegel Online in reference to the alleged activities of the U.S. National Security Agency in Germany.

"The chancellor alone is responsible for this government," Green Party leader Claudia Roth told the Nuernberger Nachrichten newspaper. The comments by Gabriel and Roth indicate an alliance between the two parties may already be in the works, analysts said.