BERLIN (Reuters) - Chancellor Angela Merkel’s plan for an orderly succession is in ruins and the chances of an early election in Germany have risen after her conservative protegee, Annegret Kramp-Karrenbauer, gave up her ambitions for the top job.

Merkel’s Christian Democrats (CDU) will in the coming months choose who they want to lead the party and run as chancellor in the next federal election, due by October 2021. The same person will probably, but not necessarily, hold both posts.

It is to early to forecast how the situation will play out, but following are three possible scenarios.

1. MERKEL OUT, NEW ELECTION WITHIN SIX MONTHS

Merkel, an anchor of stability in Europe’s biggest economy during her nearly 15 years in office, has said she will not seek re-election and stood down as party chair in 2018, handing over to Kramp-Karrenbauer.

But with the new possibility of a rival as party leader following Kramp-Karrenbauer’s exit, Merkel might be forced to stand down early, which could prompt her Social Democrat (SPD) coalition partners to walk away and trigger a snap election.

Pressure to get the issue sorted out quickly and to have the same person fill both posts could bode ill for Merkel.

Leading contenders for the CDU party chair and to be the chancellor candidate of the conservative “Union” alliance, compromising the CDU and its Bavarian sister party, Christian Social Union (CSU), are already circling.

Several senior conservatives, including CSU chief Markus Soeder, have urged the CDU to decide on its leadership soon, arguing that dragging out a contest until a party conference in December would hit the Union’s poll ratings.

FILE PHOTO: German Chancellor Angela Merkel speaks to the media before talks with Hungarian Prime Minister Viktor Orban at the Chancellery in Berlin, Germany, February 10, 2020. REUTERS/Hannibal Hanschke

Support for the CDU in the eastern state of Thuringia has plummeted by nearly 9 percentage points since its lawmakers last week broke a post-war taboo and voted with the far right to install a state premier. Nationally, support is also ebbing.

Concern over such a decline might mean that the CDU acts by the summer or early autumn to choose a new leader and chancellor candidate such as Friedrich Merz, a long-time arch-rival of Merkel, with whom the chancellor may find it impossible to work.

For its part, the SPD may refuse to work with right-wingers Merz or Jens Spahn - especially if one of them was to replace Merkel as chancellor before an election - and pull the plug on the coalition, sending Germany to the polls.

2. MERKEL STAYS THROUGH EU PRESIDENCY; ELECTION EARLY 2021

Stability-loving Germans, however, prefer gradual change and want to avoid voting in the middle of Germany’s presidency of the European Union in the second half of 2020.

Many conservative and Social Democratic lawmakers would like Merkel to play a leading role in negotiations with post-Brexit Britain and in shaping EU relations with China which will be top of the EU agenda in the presidency.

Merkel has declared she is looking forward to the EU presidency where she can employ her negotiating skills and deep experience in EU affairs - from the euro zone debt crisis to the 2015 influx of migrants. The presidency could help the conservatives show off their credentials ahead of an election.

Another factor is Merkel’s largely undiminished popularity. Pollsters say many voters view her almost as a presidential figure and would prefer her to serve a full term.

All of this increases the chances of Merkel staying at least until the end of the year but could also allow a new leader to benefit from a bounce in the polls.

3. MERKEL SERVES FULL TERM, ELECTION IN AUTUMN 2021

Even if the CDU makes its leadership decisions quickly, some candidates could work with Merkel until the end of her term although she would be something of a lame duck.

Continuity candidate Armin Laschet, premier of the state of North Rhine-Westphalia, is one such candidate and as a centrist would probably also be acceptable to the SPD.

This could also be the case if the conservatives pick Bavaria’s Soeder to run as chancellor.

Although many regard Soeder as a strong candidate, no CSU leader has yet been German chancellor.