Berlin: German President Joachim Gauck said Monday that he would not stand for a second term, creating a political headache for Chancellor Angela Merkel ahead of an election year.
The popular Gauck, 76, who has held the largely ceremonial post of head of state since 2012, made the announcement at Berlin`s Bellevue Palace, citing his advanced age.
"I`m grateful to be doing fine," he said, after speculation about health concerns.
"At the same time, I am aware that the life phase between 77 and 82 is a different one than the one I am in now. I cannot guarantee that I would have the same energy and vitality for another five-year term."
Gauck, a charismatic Protestant pastor, rose to prominence as a human rights activist in communist East Germany and was instrumental in the movement which helped topple the Berlin Wall in 1989.
His decision not to run for a second mandate complicates the political equation for Merkel, who will have to fill the job just as campaigning for the general election, expected to be held in September 2017, kicks off.
"The search for a successor will start the general election campaign more than 15 months before the poll -- a conflict that the chancellor would have preferred to avoid," news website Spiegel Online said.
Merkel immediately expressed regret about Gauck`s decision and said she would "calmly" discuss a pick to replace him with leaders of her conservative bloc as well as the opposition.
"For now we are just looking forward to a few more months of President Gauck`s term," she said.
Even before Gauck`s announcement, speculation about who would replace him was fervent, although commentators bemoaned the exit of a towering figure of German postwar history.
"Seldom have we seen someone with his personality in politics. His departure also heralds the end of a generation that shaped Europe`s identity," the daily Sueddeutsche Zeitung said. Parliament would elect Gauck`s successor in February 2017, with conservatives mentioning Finance Minister Wolfgang Schaeuble, parliamentary speaker Norbert Lammert, and Bavarian MP Gerda Hasselfeldt, a close Merkel ally who would be Germany`s first female president, as possible candidates.
Berlin`s Tagesspiegel newspaper said the horsetrading that is expected in backing a candidate for president was "sure to send a signal" about likely coalitions after the general election.
It said that if Merkel`s Christian Democrats had to seek the backing of the opposition Greens to win a majority for their pick, it could lay a foundation for an unprecedented coalition between the parties at the national level.
Merkel, who has been in power since 2006, has not yet announced whether she herself will stand for a fourth term.
She is currently in a left-right grand coalition with the Social Democrats (SPD) but their plummeting support and a desire for more dynamic alliances could push Merkel`s conservatives toward the ecologist Greens.
"If Merkel now wants to prevent an SPD candidate, then she will have to find someone who also appeals to the Greens," the right-leaning broadsheet Frankfurter Allgemeine Zeitung wrote.
"That should be manageable."
Such a scenario would also block the potential development of a left-wing alliance between the SPD, the Greens and the hard-left Linke party.
The choice of Hasselfeldt, meanwhile, could help heal a rift between the Christian Democrats and their Bavarian sister party, the Christian Social Union (CSU), which has been sniping at Merkel`s refugee policy for several months.
The dispute has prompted speculation the CSU could field its own candidate for chancellor rather than backing Merkel.
Unity on the right could then help fend off a growing challenge from the anti-immigration Alternative for Germany (AfD) party, which is currently polling at about 15 percent, analysts said.