BERLIN (Reuters) - After Chancellor Angela Merkel and European Central Bank President Mario Draghi, German Finance Minister Wolfgang Schaeuble has wielded perhaps the most influence during Europe's debt crisis.
He seems certain to keep his job if Merkel is able to continue her coalition with the Free Democrats (FDP) after a German general election on Sunday, people close to Merkel say.
But should she fall short of a center-right majority, it is unclear whether Schaeuble will be able to stay on, or who might take his place.
Days before Sunday's vote, polls show the center-right may struggle to keep its majority. The most likely scenario if it doesn't is a repeat of the 'grand coalition' with the Social Democrats (SPD) that Merkel led between 2005 and 2009.
Following is an outline of potential contenders for the important finance minister post:
WOLFGANG SCHAEUBLE (CHRISTIAN DEMOCRATIC UNION)
Schaeuble, one of Germany's most popular politicians, said in June he wanted to keep his job and should Merkel's coalition with the liberal FDP survive after September 22, it is probably his for the taking.
In a coalition with the SPD, his chances would depend on whether the junior partner lays claim to the post. A score close to 30 percent would increase the Social Democrats' chances of taking the finance ministry which they held from 1998 to 2009.
Wheelchair-bound since an assassination attempt in 1990, Schaeuble has recovered from health problems two years ago and wields huge clout among European Union policymakers handling the euro zone debt crisis. His sharp intellect, lawyer's mind and influence in the CDU's southern power base have helped Merkel.
Financial markets would likely welcome his return.
SIGMAR GABRIEL (SPD)
The SPD is likely to enter coalition talks with its sights on both the finance and foreign ministries, but getting both -- as the party did in 2005 -- may depend on the party polling close to 30 percent.
As party chairman, Gabriel would normally be first in line to become vice-chancellor and get first pick of a cabinet role.
SPD sources say Gabriel, 54, a former environment minister, is interested in the post though he is not a finance expert. Pushing Schaeuble from the key position would be seen as a coup.
But Gabriel may prefer the foreign ministry, the traditional choice of junior coalition partners, or the labor ministry, an old SPD favorite. He may also choose to stay out of government altogether, for example leading the SPD in parliament.
If the SPD polls close to its record low of 23 percent in 2009, Gabriel could find himself booted out as SPD leader and lose his chance of a ministry.
Gabriel is not the markets' preferred choice. Being finance minister means working closely with the chancellor, and their relationship was strained when Gabriel made public a confidential text message she sent him in 2010.
FRANK-WALTER STEINMEIER (SPD)
Steinmeier, who was vice-chancellor and foreign minister in the last "grand coalition" in 2005-2009, would be a more consensual choice but he may not want the job.
He has voiced frustration with Merkel's leadership style and may want to focus on rebuilding the SPD's support to prepare a return to power in 2017, the next federal election.
His power base is in parliament, where he leads the SPD opposition, and party insiders say the 57-year-old trained lawyer has been quietly campaigning to stay put.
A capable, detail-oriented foreign minister and moderate within the SPD, Steinmeier would be seen as a safe pair of hands although he has no financial expertise.
PEER STEINBRUECK (SPD)
The SPD's candidate for chancellor, who worked well with Merkel as finance minister in the last "grand coalition", has categorically ruled out serving under her again and is expected to stick to his word.
However, if the SPD enters coalition talks with the CDU, he will stay on to lead the negotiations. This might open the door for him to change his mind.
Former SPD chancellors Helmut Schmidt and Gerhard Schroeder said it may not have been smart for the 66-year-old to rule out a second spell as minister. That has sparked speculation about a repeat of the successful partnership of 2005-2009.
As a former finance minister and SPD moderate, Steinbrueck would also be seen as a safe pair of hands.
JOERG ASMUSSEN (SPD)
The European Central Bank board member and former deputy finance minister has an outside chance of the job if the SPD wins the post in coalition talks but no heavyweight politician chooses to take it.
The 46-year-old technocrat is an effective backroom negotiator and has Merkel's ear. He served five finance ministers, including Steinbrueck and Schaeuble, and has played a key role in managing the euro zone crisis, both at the ministry and at the ECB since early 2012.
But he has never held political office, is not a member of parliament and has no power base within the SPD. Party elders could be reluctant to give him this prime post.
"He has the qualifications," said one German official who has worked with Asmussen. "But my experience is that members of parliament don't like non-MPs taking ministries away from them. He would have a tough time with that."
His experience could also make Asmussen a good fit for a senior advisory post in the Chancellery, though Merkel and her conservative entourage may be reluctant to bring an SPD member into the heart of power.
JUERGEN TRITTIN (GREENS)
Given the Greens' drop in opinion polls and their leftist stance in the campaign, speculation about a coalition with Merkel's conservatives has faded. In the unlikely event that they formed a government together, the Greens would demand key cabinet posts and party leader Trittin has his eye on the finance ministry.
(Reporting by Annika Breidthardt, Noah Barkin, Holger Hansen and Andreas Rinke; Editing by Stephen Brown and Paul Taylor)