BERLIN, Sept 10 Angela Merkel may be the most powerful woman in Europe, but this week the chancellor's plans to save the euro lie in the hands of Andreas Vosskuhle, the supreme court judge known as Germany's most powerful man.
In a ruling with global ramifications, the Constitutional Court is expected on Wednesday to allow an EU bailout fund and budget pact, although most legal experts expect it to impose conditions to show that parliament controls Germany's budget.
Wednesday's verdict will test the authority of the court, and of Vosskuhle, its youngest ever president at 48, a pragmatist who must balance the issue's weighty theoretical questions with its tremendous real world consequences.
"The pressure is on, he knows that. But for him it is part of a job that he takes very seriously," one of his colleagues said privately, adding that Vosskuhle's "pragmatic openness" stood him in good stead to reconcile any competing views among the eight "diva-like" judges considering the case.
The principle that parliament has supreme authority is fundamental to a post-Nazi constitution designed to ensure Germans are never again denied democratic rights. Vosskuhle's court has repeatedly held Merkel's government to account in the past over whether EU treaties break this rule.
But Vosskuhle will also be well aware of the stakes for politicians - desperate to keep tools they believe are needed to fight the debt crisis - and for financial markets - which would surely panic if the euro rescue measures were blocked.
Surveys show Germans trust the judges to get it right. Legal experts expect a nuanced judgment that may let Merkel pursue her policy now while setting limits for the future.
The court must determine whether the government can sign Germany up to the European Stability Mechanism fund, intended to provide bailout funding for weaker euro zone states, and a fiscal pact that gives Brussels authority over deficits.
Not a single legal expert in a Reuters poll believed the court would rule the measures unconstitutional. But Vosskuhle has indicated that Merkel has been pushing at the limits of what can be done without a historic change in the constitution.
In a rare media interview a year ago, he said Germany's scope for shifting power to the European Union institutions in Brussels had "probably been largely exhausted".
Vosskuhle is aware that to sink Europe's joint bailout fund would be "the most momentous decision the court has taken in its entire history," said public law professor Mattias Kumm. "And it makes him sceptical about going down that route."
In his two and a half years as court president, Vosskuhle has won respect for rulings which balanced parliament's sovereignty with the political expediency of letting the government work with European peers to save the single currency. A move in July to set more time to make a ruling impressed many as deftly diplomatic.
Plucked from academia in 2008 to sit on the court in the southwestern town of Karlsruhe, Vosskuhle is a declared supporter of European integration.
Though not a party member, he acknowledges an affinity with Social Democratic values. He was nominated by Merkel's centre-left opponents, who have generally been more supportive of the euro than some in the chancellor's own conservative bloc.
Large black-rimmed spectacles and chubby cheeks give him boyish looks that may seem out of keeping with the gravity of his office. But he speaks with great earnestness about what he sees as a mission to defend democracy in a nation still marked by a history that saw it give up individual rights.
"Democracy has its price," Vosskuhle said in June. "But cutting back on it could be very expensive," he said.
Kumm, head of the Rule of Law Centre at Berlin's Social Science Research Centre, said Vosskuhle is "in touch with global integration - he endorses and embraces it," but added: "But he believes politicians should get people involved."
In a series of rulings on EU integration under Vosskuhle, the court has demanded a bigger say for parliament, delaying but stopping short of blocking Merkel's policies becoming law.
That has reinforced perceptions of the court as a dog that barks but doesn't bite, a tag that annoys Vosskuhle a great deal, according to one person who knows him.
He is certainly not afraid of upsetting politicians in Berlin. The court's most closely scrutinised ruling under him was a 2009 decision on the European Union's Lisbon Treaty which changed the bloc's constitutional framework.
The court delayed the treaty's implementation by ruling that parliament's role in EU decision-making had to be enhanced.
Though he says he "feels close to Social Democracy", he is known to have a good relationship with the conservative Merkel. She even touted him as a candidate for the figurehead role of president this year. Media reported he was not tempted.
Vosskuhle was born in 1963 in the northern town of Detmold and followed his father into the legal profession. His wife is also a lawyer.
Amiable but serious-minded, Vosskuhle avoids dominating his colleagues and is not confrontational, say people who know him. His office does not give him a deciding vote over his fellow judges, who sit dressed in red robes and traditional hats.
"Whoever likes duelling should go to the cinema," Vosskuhle is quoted as saying.
He may eschew competitive machismo, but his quiet, diplomatic style is effective, say colleagues. He is skilled at his main job of bringing together a group of strong-minded judges, said the person who works with him.
As an amateur chef, Vosskuhle is said to gather guests in his kitchen, get them to chop vegetables over a glass of wine and together concoct a dish relished by everyone.
"Vosskuhle stirs the dressing himself," wrote the Sueddeutsche Zeitung newspaper. "You can imagine how he operates as top judge."