BERLIN (BLOOMBERG) - Mr Armin Laschet clinched the nomination to run for German chancellor for Dr Angela Merkel's conservative bloc, ending a messy stand-off that threatened to damage the country's strongest political force.

Mr Laschet, the head of Dr Merkel's Christian Democratic Union (CDU), becomes the favorite to lead Europe's biggest economy following September's election after fending off an insurgent challenge from Mr Markus Soeder, the leader of the smaller Bavarian sister party.

After a clear vote by the CDU's leadership backing Mr Laschet early on Tuesday (April 20), Mr Soeder conceded.

"The dice have fallen. Armin Laschet will be the chancellor candidate" of the conservative alliance, Mr Soeder said, adding that he had called Mr Laschet and congratulated him.

"I have offered him the full support of the CSU for this extraordinarily difficult election campaign. We will support him with all our power, without any resentment."

By picking the 60-year-old moderate, Germany's conservatives are foregoing Mr Soeder's greater electoral appeal and making a potentially risky bet that Mr Laschet will be able to lift his flagging poll numbers. The decision sets up a tight race against the Greens, which have surged in the polls and are closing in on the bloc.

While Mr Soeder, 54, has much more support among voters, rejecting Mr Laschet less than three months after he was picked as leader of the CDU would have created a whole new set of problems - including destabilising the party hierarchy and undermining its campaign in North Rhine-Westphalia, Germany's most populous state, where Mr Laschet is premier. And the testy contest could still leave scars.

"It's now about standing together and coming together," Mr Soeder said. "There will certainly be arguments, but we will make our contribution to our joint success."

The fact that Germany's dominant party wound up in such a mess with just five months to go to polling day reflects its struggle to move past 66-year-old Dr Merkel, who has governed for 16 years and dominated the CDU for a generation.

While it is still on track to be the biggest party in the next parliament, the latest polls indicate that the CDU/CSU is heading for its worst-ever result in a federal election and is facing a challenge by the Greens to become Germany's strongest force.

That leaves Mr Laschet with little time and little margin for error.

Ms Annalena Baerbock, a 40-year-old political scientist and foreign-policy expert, was named the Greens' first official chancellor candidate on Monday. She claimed the mantle as the candidate for change and took issue with the "mudslinging" in the conservative bloc.

"Trust in democracy, in politics as a whole is threatened," she said. "I stand for renewal. Others represent the status quo."

An initial effort to hand over the reins to Dr Merkel protege, Ms Annegret Kramp-Karrenbauer, was undermined by a series of missteps and then the process of selecting a replacement was delayed by the Covid-19 pandemic.

Mr Laschet was elected in January and promptly suffered bruising defeats in elections in former conservative strongholds. That opened the door for Mr Soeder, who fought tooth and nail to prevent his rival from settling the debate, potentially doing lasting damage to the bloc's image.

Mr Laschet will need to reclaim the conservative's reputation as the anchor of German stability. He won the candidacy mainly for his consistency in contrast to Mr Soeder's reputation for flip-flopping and opportunism.

The son of a coal mining foreman, Mr Laschet graduated in law, once edited a Catholic newspaper and was a legislator in the Bundestag as well as the European Parliament before being elected leader of Germany's most populous state in 2017.

He will likely continue Mr Merkel's centrist policies as well as her low-key style of leadership, if he wins in September and can form a ruling coalition. Yet he will inherit a raft of new challenges, ranging from overcoming the coronavirus pandemic to managing a transition to green technology and tackling the threats posed by China and Russia.

"Ranks are closing behind Armin Laschet," Mr Roderich Kiesewetter, a CDU lawmaker, said in an interview with ZDF television on Tuesday. "We now have to look forward" and turn attention to the campaign.