Senior members of Chancellor Angela Merkel's conservatives gathered on Monday to decide on a leadership accession plan, after a state election drubbing in Hamburg added urgency to their search.

Voters handed Ms Merkel's conservative Christian Democrats (CDU) their worst-ever result in Hamburg on Sunday, punishing them for flirting with the far-right in an eastern state and descending into a messy leadership battle.

The succession debate was blown wide open earlier this month, when CDU leader Annegret Kramp-Karrenbauer unexpectedly said she would no longer seek to succeed her mentor Ms Merkel.

Mass-selling daily Bild dubbed the Hamburg result a “debacle” for the CDU, whose leadership crisis has raised questions over the future course of Europe's largest economy.

The CDU slipped into third place in Hamburg, scoring just 11.2 per cent in the northern port city, behind the Social Democrats (SPD), for whom the city is a stronghold, and the Greens.

The iron Frau: Angela Merkel Show all 11 1 /11 The iron Frau: Angela Merkel The iron Frau: Angela Merkel Comeback queen: Angela Merkel at the Bellevue Palace, Berlin in 2007 EPA / WOLFGANG KUMM The iron Frau: Angela Merkel At home in Germany, the press are comparing Merkel to Margaret Thatcher (pictured in 1981), for her tough-talking stance on the Greek debt crisis GETTY IMAGES / REUTERS The iron Frau: Angela Merkel What Cold War? With Vladimir Putin and George W Bush in 2007 at a G8 summit in Germany. She's known to be an entertaining mimic; was she doing her 'Gordon Brown' for them? AFP The iron Frau: Angela Merkel The famous clip that showed George W Bush squeezing her shoulder The iron Frau: Angela Merkel Whispering with Silvio Berlusconi REUTERS The iron Frau: Angela Merkel Make 'em laugh: with Nicolas Sarkozy AFP The iron Frau: Angela Merkel Crowd-pleaser: Merkel's supporters at a 2009 election rally AFP / GETTY IMAGES The iron Frau: Angela Merkel Immortalised in doll form The iron Frau: Angela Merkel With other world leaders at last year's G20 summit AP The iron Frau: Angela Merkel With her husband Joachim Sauer EPA The iron Frau: Angela Merkel Campaigning in 1990 REUTERS

“The dismal result for Merkel's centre-right CDU... adds to the pressure on the party to resolve the leadership crisis fast,” Berenberg bank analyst Holger Schmieding said.

Nationally, the Greens are second, behind Ms Merkel's conservative bloc, and many commentators expect them to have a role in the next federal government.

Ms Merkel, chancellor for almost 15 years, has said she will not run again in the next federal election, due by October 2021.

Kramp-Karrenbauer's decision to give up her ambition of succeeding Ms Merkel came after an eastern branch of the CDU defied the national party and voted with the far-right Alternative for Germany (AfD) to install a state premier from a third party.

That broke a postwar consensus among established parties of shunning the far right.

Kramp-Karrenbauer will brief reporters after Monday's meeting of senior CDU officials and is expected to set out a timetable for a decision on the party chair and possibly the candidate for chancellor.

The broadcaster n-tv cited CDU sources as saying the party will hold an extraordinary congress either in April or May to elect a new leader.

Four or five candidates are jockeying for the jobs.

Daniel Guenther, premier of the northern state of Schleswig-Holstein, told broadcaster SWR that the CDU should clear up the leadership question quickly and hold a party conference “well before the summer break”.