Centrist Armin Laschet positioned himself on Saturday as the man to heal divisions among Angela Merkel's Christian Democrats after they chose him to lead the party, putting him in pole position to succeed her as Germany's chancellor. And he will need to plunge straight into an electoral marathon that culminates with the September 26 national vote.

Dr Merkel said previous year that Mr Laschet had "the tools" to run for chancellor, the closest she has come to endorsing anyone. He didn't address his plans at Saturday's party convention.

Laschet, 59, was elected in 2017 as governor of North Rhine-Westphalia state, a traditional centre-left stronghold. Current polls point to the environmentalist Greens as a possible key to power in the election.

Alternative for Germany co-leader Joerg Meuthen said Laschet's election means the CDU "will carry on Merkeling" and asserted that his party "remains the only conservative party in Germany".

Laschet and Roettgen are expected to continue with Merkel's more moderate centrist course.

"As a people's party of the centre, we naturally seek solutions that balance out conflicts and always promote. social cohesion", Merkel told delegates at the opening of an online conference to pick the party's next leader. "By polarizing, sowing discord and distrust, and systematically lying, a president has destroyed stability and trust".

The party leadership was supposed to have been settled in April. A third candidate, prominent legislator Norbert Roettgen, was eliminated in a first round of voting.

Merz's sizeable support suggests that a strong contingent would like a sharper conservative profile after the Merkel years.

At a meeting of senior members of her centre-right CDU party, the German Chancellor said she wanted to bring forward crisis talks with regional leaders to "the coming week", participants told AFP. She has also broken repeatedly with conservative orthodoxy, for example by accelerating Germany's exit from nuclear energy and ending military conscription. "The Chinese economy was smaller than Germany's - it is now nearly four times bigger", she added. She described the pandemic as a "once-in-a-century" event.

The party conference in a digital format is a novelty due to the ongoing COVID-19 pandemic.

Her legacy must be preserved and combined with new ideas, he said.

The 66-year-old, elected as Germany's youngest and first female chancellor in 2005, is planning to stand down after four terms and 16 years in the job following a general election in September.

But after his narrow run-off victory, Mr Laschet must move swiftly to unite the party or risk eroding its support and leaving it in a weaker position to negotiate a coalition should it - as now predicted - come first in September's elections. The Union now has a healthy poll lead, helped by positive reviews of Merkel's handling of the pandemic.

Green Party leaders Annalena Baerbock and Robert Habeck said Laschet must redefine the CDU and set a course to modernise the economy in an environmentally sustainable way.

However, polls show Mr Markus Soeder, the CSU leader, is the conservative most favoured by voters.

While she did not name names, the call appeared to indicate support for Laschet, who has campaigned on a joint ticket with Health Minister Jens Spahn as his deputy.

"It's very good that a year-long discussion process is over", Soeder said.