BERLIN (Reuters) – The woman who had been expected to become Germany’s next chancellor has decided not to run for the top job, a source in her Christian Democratic party (CDU) said on Monday, throwing into confusion the race to succeed Angela Merkel. Annegret Kramp-Karrenbauer is CDU leader and a protegee of the chancellor but has faced growing doubts over her ability to replace Merkel, who has led Germany for 15 years but plans to stand down at the next federal election, due in autumn 2021. Last week Kramp-Karrenbauer’s inability to impose discipline on the CDU in the eastern state of Thuringia dealt a fresh blow to her credibility. The regional CDU branch defied her by backing a local leader helped into office by the anti-immigrant Alternative for Germany (AfD), thereby shattering a postwar consensus among established parties of shunning the far-right. Kramp-Karrenbauer’s decision not to run for chancellor leaves a big question mark over Germany’s future direction just as its economy, Europe’s largest, flirts with recession and as the EU struggles to define itself after Brexit. The CDU source, speaking on condition of anonymity, said Kramp-Karrenbauer – often dubbed AKK after the initials of her name – would remain party chair until another candidate for chancellor has been found. She believes the same person should serve as both chancellor and party leader and will organize a process in the summer to fill both roles, the source added. Kramp-Karrenbauer wants to remain as Germany’s defense minister and Merkel supports her on that, a German government spokesman said. Sigmar Gabriel, a former leader of the Social Democrats (SPD), junior partner in Merkel’s ruling coalition, said he expected a snap federal election as the two main parties – the conservatives and the SPD – are struggling to unite their different factions. “I expect it won’t be long before there are new elections,” Gabriel told mass-selling daily Bild. Michael Roth, a senior SPD member, said on Twitter: “After the announced withdrawal of @akk, it is even more uncertain whether decent democrats will stand together across party lines in the fight for democracy & against nationalism. Disturbing.” RIVALS CIRCLE Kramp-Karrenbauer, 57, won a vote in December 2018 to succeed Merkel as CDU leader, though many remained unconvinced of her leadership credentials. Kramp-Karrenbauer’s erstwhile rivals for the party leadership – Friedrich Merz and Jens Spahn – have been circling with intent. Businessman Merz has quit asset manager Blackrock to focus more on politics and Spahn, now health minister, has cut a dynamic figure during the coronavirus crisis, jetting to Paris and London to coordinate the European and G7 response. On Monday, shortly after news broke of Kramp-Karrenbauer’s plan to step aside, Merz tweeted: “Now’s the right time to provide impetus via economic and financial policy measures.” He said cutting taxes would boost private households’ purchasing power and the ability of companies to invest. Related CoverageMerkel supports Kramp-Karrenbauer in her desire to remain defense minister: spokesmanMerkel protegee will remain CDU chair until a chancellor candidate is found: sourceSee more stories Alexander Gauland, honorary chairman of the far-right AfD, welcomed Kramp-Karrenbauer’s move. Gauland said she had failed to implement the CDU’s policy of ostracising the AfD and added that such an approach was unrealistic in the long-term. “Its party base has long since recognized this and has thrown the CDU, with its policy of exclusion, into chaos “ he added. Merkel has loomed large on the European stage since 2005, helping guide the EU through the euro zone crisis and opening Germany’s doors to migrants fleeing war in the Middle East in 2015 – a move that still divides the bloc and her country.