Senior members of German Chancellor Angela Merkel's ruling Christian Democratic Union warned Saturday the party was in crisis as it tries to keep its distance from both the hard right and left.

The issue has come to a head in recent weeks in the small eastern state of Thuringia, where uproar followed a move by CDU regional lawmakers to join the far right AfD in voting to oust a popular Left party politician as state premier.

The breaching of a "firewall" preventing any cooperation between centrist parties and the anti-immigrant AfD has sparked soul searching on both wings of the CDU.

An identity crisis now threatens to engulf the party after Merkel's anointed heir Annegret Kramp-Karrenbauer was forced to renounce her leadership ambitions after failing to hold a clear party line on the issue.

"We are going through a crisis of confidence," Health Minister and rising party star Jens Spahn said Saturday.

With Angela Merkel in the twilight of her tenure as chancellor, her party is struggling to assert its identify in the face of growing far right violence and work out how to deal with the anti-migrant AfD
With Angela Merkel in the twilight of her tenure as chancellor, her party is struggling to assert its identify in the face of growing far right violence and work out how to deal with the anti-migrant AfD AFP / kenzo tribouillard

"This is about the CDU's credibility in Germany," ahead of elections which must take place by next year, added party secretary general Paul Ziemiak.

Thuringia may be home to barely two percent of the population of Europe's largest economy -- but it highlights the pressures building on a party ruling in an already uncomfortable coalition at national level with the Social Democrats.

There will be a March 4 re-run in the state after a pro-business Free Democrat, a traditional CDU ally, stepped down having been elected regional president with dual CDU and AfD backing.

The row on the regional CDU voting alongside the AfD in Thuringia's election cost Annegret Kramp-Karrenbauer her dream of taking over from Merkel -- Health Minister Jens Spahn says their party is in crisis
The row on the regional CDU voting alongside the AfD in Thuringia's election cost Annegret Kramp-Karrenbauer her dream of taking over from Merkel -- Health Minister Jens Spahn says their party is in crisis AFP / Odd ANDERSEN

That will likely mean the re-election of the Left's Bodo Ramelow, denied by last month's controversial initial vote, to head a minority leftist government until fresh local elections next April.

But Ziemiak warned Saturday that CDU support for Ramelow would break with official party policy of neither backing far right nor far left.

"Anybody who votes in favour of Ramelow as regional government head goes against CDU polices," said Ziemiak.

The CDU's confused stance in Thuringia has already forced out regional party head Mike Mohring.

Wolfgang Schaeuble, the CDU's former Interior minister and now Bundestag president, ruled out "any cooperation between the CDU" and the Left as the latter "is the legal successor of the old SED," the old East Germany's ruling party -- even if Ramelow is a moderate leftist.

Current Interior Minister Horst Seehofer on Friday warned right-wing extremism was the "biggest security threat facing Germany" after Wednesday's racially motivated shootings in the Frankfurt suburb of Hanau, which gave rise to nationwide protests.

The rise of forces beyond the centre right and centre left has left Germany's traditional parties facing an almost impossible balancing act, the political spectrum now salami-sliced to a degree which makes forming majorities ultra complicated both nationally and regionally.

Left supporters are meanwhile outraged at also being placed beyond the CDU's "firewall," essentially as undesirable as a far right which most CDU leaders view as a political home for "Nazis" or "fascists."

Monday will see the embattled CDU lay out a timetable for candidates seeking to take the party forward post-Merkel but also address strategy for Thuringia, both issues deeply entwined.

Germany