The CDU is at the crossroads. It is a question of the union's existence

CDU leader Angela Merkel

Ms Merkel pleaded for an end to the divisive debate over the party's candidate for chancellor in next year's elections.

The weekend saw members of her own party voicing increasingly blunt criticism of her leadership as supporters of her two rivals - Wolfgang Schaeuble and Edmund Stoiber - pushed them forward as candidates for the top job.

"The CDU is at the crossroads," Ms Merkel said at the weekend. "It is a question of the union's existence."

She warned that the debate over who the party would back for the chancellorship was endangering its electability.

Nerves and backstabbing

But even as she spoke, it emerged that a regional party conference had already voted against Ms Merkel to stand as the party's candidate next year.

Every time when we are half way back on our feet again, we get a kick in the back from the Bavarian woods

Angela Merkel

Senior CDU politicians on Monday came out in support of Ms Merkel, condemning the open flouting of her authority.

But the secretary general of the Bavarian sister party, the CSU, Thomas Goppel, in return criticised Ms Merkel's "sensitive reaction," which he said was a sign of her "raw nerves".

Ms Merkel had particularly targeted Mr Goppel who, she said, had been pushing Wolfgang Schaeuble as a candidate.

Wolfgang Schaeuble: Rehabilitated since prosecutors dropped charges

"Every time when we are half way back on our feet again, we get a kick in the back from the Bavarian woods," she said.

Mr Schaeuble has been openly touted as a potential candidate since last week prosecutors dropped charges against him in connection with the slush-fund scandal that has dogged the party since the end of the Kohl era.

Mr Schaeuble took over as CDU party leader from Mr Kohl after the 1998 election defeat, but was forced to resign shortly afterwards when he too became embroiled in the scandal.

The other main runner - right-wing Bavarian premier Edmund Stoiber - is also considered a much stronger candidate than Ms Merkel who has struggled since she took office to gain authority within the party.