German state election a test for Chancellor Merz
Voters will head to the polls in the southwestern state of Baden-Wuerttemberg, a prosperous hub of Germany's flagship auto sector with a population of 11.2 million.
The CDU, a year after winning national elections, hopes to snatch first place in Baden-Wuerttemberg back from the Greens, who have won the last two state elections.
Merz's party until recently enjoyed large poll leads in the state but these have shrunk in recent months.
The most recent survey put the CDU and the Greens in a dead heat on 28 percent.
Leading the CDU into the poll is 37-year-old Manuel Hagel, a former bank branch manager whose campaign hit a rough patch over comments he made about female students during a school visit in 2018 which were judged sexist and inappropriate.
He has since apologised for the remarks.
The Greens' lead candidate is Cem Ozdemir, 60, who, if he wins, would become Germany's first state premier of Turkish heritage.
The AfD has been polling at 18 percent, which would be a record score for the anti-immigration party in Baden-Wuerttemberg but still short of its national poll figures of around 25 percent, similar to those of the CDU.
On Friday Merz attended the CDU's final campaign rally and said the vote would be watched outside Germany to answer the question: "Is the CDU still able to win elections, even when in government at such a turbulent time?"
The state was traditionally a CDU stronghold, and a poor showing would be an inauspicious start for Merz's party to a year of regional votes in which it hopes its tougher migration policy will win back AfD voters.
On March 22, it hopes to beat the centre-left Social Democrats (SPD) in the western state of Rhineland-Palatinate.
In September will follow a series of regional votes in ex-communist eastern Germany, where the AfD can expect to perform well.
'Avoiding' key issues
Baden-Wuerttemberg is home to some of the biggest names of Germany's important but ailing car industry, such as Porsche and Mercedes-Benz.
Here, as elsewhere in Germany, the sector has been battling challenges ranging from high energy prices to increased competition from China.
Brian Fuerderer, 34, the head of a local company making surgical equipment, told AFP he found the electoral campaign "weak".
He said the parties were "avoiding the most essential issue... the economy" as well as the country's dependence on foreign energy supplies, thrown into stark relief by the Middle East war.
Merz says that boosting Germany's moribund economy is his key priority and to that end lobbied the EU to weaken its ban on new combustion-engine cars after 2035.
Even the Greens' Ozdemir has said there should be more flexibility in the transition to electric vehicles.
Ozdemir has a national profile in Germany, having become one of the first MPs of Turkish origin in 1994 and serving as agriculture minister under former SPD chancellor Olaf Scholz.
If the Greens do come out on top on Sunday, Ozdemir would be poised to take over from current state premier and party colleague Winfried Kretschmann, 77, who has led the state for 15 years.
Ozdemir comes from the Greens' "realist" tradition and has signalled his distance from more left-wing factions of his party.
"Not every idea that comes from my party is always correct," he recently told public broadcaster ZDF.
The AfD's lead candidate, Markus Frohnmaier, has attracted national attention with his links to Russia and US President Donald Trump's Make America Great Again (MAGA) movement.
Recently he approvingly posted on the X platform about a poll putting the party on 20 percent in Baden-Wuerttemberg.
Such a result would be "sensational" for the party, he said, and the best it had ever scored in a western German state.