Germany's Social Democrats on Thursday called on Chancellor Angela Merkel to sack the country's top spy, as a controversy over him risks snowballing into a new crisis threatening the uneasy coalition.
Hans-Georg Maassen, who heads Germany's domestic intelligence agency BfV, has been caught in the headlights after he appeared to minimise violent far-right protests in the city of Chemnitz.
Merkel had firmly condemned a "hunt against foreigners" backed by videos circulating on social media, but Maassen directly contradicted her by questioning the authenticity of at least one of the clips before backpedalling.
For critics, Maassen's claim played into the hands of rightwing extremists.
Questions were also raised about Maassen's intentions as he had previously been accused of meeting with leaders of the far-right AfD party to give them advice on how to avoid being placed under official surveillance -- allegations that he has rejected.
On Thursday, new accusations emerged against him with an AfD MP saying Maassen gave him unpublished official data.
Interior Minister Horst Seehofer of Merkel's Bavarian allies, the CSU, has so far thrown his weight behind Maassen.
But the Social Democratic Party (SPD), the third party in Merkel's coalition, said Maassen's position had become untenable.
Lars Klingbeil, SPD general secretary, said: "It's absolutely clear to the SPD leadership that Maassen has to go. Merkel must take action."
As the discord over Maassen deepened, Merkel is due to hold talks later Thursday with Seehofer and SPD chief Andrea Nahles.
Maassen in August 2012 took over at the Federal Office for the Protection of the Constitution (BfV) after his predecessor was forced to quit as it emerged the service had shredded files on suspects of the deadly neo-Nazi cell NSU.
As BfV chief, Maassen leads an agency charged with collecting and evaluating information on efforts to harm the democratic order or jeopardise Germany's interests.
But among his key tasks following the NSU scandal was also to restore public confidence in an institution accused of being too lax with the far-right threat and too heavy-handed on extreme left activism.
The latest episodes with the AfD and the far-right have reopened uncomfortable questions over the service's neutrality.
Maassen, a bespectacled 55-year-old, faced a grilling by two parliamentary committees on Wednesday, before Seehofer told parliament Thursday emphatically that Maassen "continues to have my trust in him" as BfV chief.
He argued that Maassen had "a convincing position against the rightwing radicalism".
But the controversy over Maassen refused to go away as AfD MP Stephan Brandner told public broadcaster ARD that the spy chief on June 13 handed him figures from his agency's latest annual report "that had not been published".
"We spoke about different figures that were in the report," said Brandner, adding that the data was related to Islamists deemed dangerous by the service as well as the agency's budget.
The BfV published its report five weeks later.
Rejecting the ARD report, a BfV spokesman said: "The report gives the impression that information or documents have been passed on illegally. That is of course not the case."
The spokesman added that Maassen holds talks with members of all parties in parliament at the request of the interior ministry.
But the SPD warned its coalition partners that it was time to let Maassen go.
Raising the stakes, the leader of the SPD's youth wing, Kevin Kuehnert said that the scandal could threaten the survival of the coalition itself.
"If the BfV president stays in his job, then the SPD can no longer keep working in the government," he told Spiegel Online.