Opposition parties in Brandenburg banded together to push for an emergency session of parliament to debate the affair on Friday.

The Social Democrat (SPD) premier, Matthias Platzeck, said his government would make a statement to parliament on the three cases at that time.

He added that the revelations connected to his coalition partners, the Left party, were "downright painful."

The vice president of the Brandenburg legislature, Gerlinde Stobrawa, and fellow Left party MP Renate Adolph resigned from their posts on Monday.

Stobrawa denied allegations, first raised in the German media, that she was an informant for the former East Germany's Ministry for State Security, or Stasi, but her party said she chose to resign to avoid harming the work of her office.

Adolph admitted to the allegations against her and said she had not had the courage to disclose her activities.

A third MP, Gerd-Ruediger Hoffmann, has refused to step aside, and wants time to consider his Stasi file.

"We have concluded that the leadership of the Left party is not responsible for any failures, let alone cover-ups," said Brandenburg SPD leader Dietmar Woidke to German media, suggesting that the so called "red-red" coalition, which was only formed a month ago, is in not in danger of collapse just yet.

But the Left party did acknowledge that it had a scandal on its hands.

"This has political fallout. This is a difficult test for the red-red (coalition)," said the head of the Left party in Brandenburg, Kerstin Kaiser.

Some members of the SPD see the party's coaliton with the Left in Brandenburg as a model to be pursued in the future at the federal level.

Until now, though, the SPD has officially ruled out the possibility of ever forming a federal coalition with the Left party, which was founded mainly by members of the successor party to the former East German Communists and disaffected Social Democrats.

nw/dpa/AFP
Editor: Chuck Penfold