The stakes are unusually high for German Chancellor Angela Merkel's government as the central state of Hesse votes in a state election this weekend.

Sunday's election has become an important test for Germany's governing parties. It may help determine whether Merkel's unhappy federal coalition in Berlin has a long-term future, and even how much longer Germany's leader of the past 13 years can carry on at the helm of the European Union's largest economy.

Nearly 4.4 million people can vote for the state legislature in Hesse, which includes Germany's financial capital, Frankfurt. Merkel's conservative Christian Democratic Union is defending its 19-year leadership of the region, long a stronghold of the center-left Social Democrats.

Those parties, traditionally Germany's biggest, form Merkel's national government in a "grand coalition" together with the CDU's Bavaria-only sister, the Christian Social Union. In an Oct. 14 election in Bavaria, the CSU and the Social Democrats were battered by voters who were turned off by constant squabbling in the seven-month-old national government.

"People are really waiting spellbound for the outcome, because depending on how it goes, there will be a lot of turbulence next week," said Thorsten Faas, a political science professor at Berlin's Free University. "It's very unlikely that both the CDU and the Social Democrats will get an unexpectedly good result."

Depending on the result, either Merkel or Social Democrat leader Andrea Nahles will likely face a discussion about their future.

"Which, in any case, means that the 'grand coalition' will really get into deep water," he said.

Parliamentary speaker Wolfgang Schaeuble, a senior member of Merkel's party, affirmed the stability of the chancellor's leadership during a trip to Israel on Thursday, telling reporters: "She's in a strong position. Compared to the results of polls in other European democracies, she's strong, much stronger than most."

Hesse is currently run by the CDU and the traditionally left-leaning Greens, the first such coalition to survive a full parliamentary term. Conservative state governor Volker Bouffier notes it has been a surprisingly harmonious alliance.

Locals appear generally satisfied with the state government but polls suggest it will struggle to keep its majority because of the CDU's weakness. The Social Democrats are doing even worse in Hesse, battling with the Greens — who are in opposition nationally — for second place.

Recent polls have shown about 26 percent support for the CDU and up to 21 percent for the Social Democrats, down from 38.3 and 30.7 percent respectively in a 2013 vote. They show the Greens as high as 22 percent, up from 11.1 percent five years ago.

The far-right, anti-immigrant Alternative for Germany party is expected to enter the last of Germany's 16 state legislatures with support of up to 13 percent in Hesse. The party entered the national parliament last year and, along with the Greens, has benefited from the federal government's disarray.

A number of governing coalitions are possible in Hesse. If the Greens do exceptionally well, they could get their second governor of a German state in Tarek Al-Wazir. The current deputy governor, the son of a Yemeni ex-diplomat and a German teacher, is one of Hesse's most popular politicians.

Bouffier is a deputy national leader of Merkel's party and his center-left challenger, Thorsten Schaefer-Guembel, is a deputy leader of the Social Democrats. Observers believe Bouffier losing power, or a disastrous result for Schaefer-Guembel, would further destabilize Merkel's federal coalition.

The Social Democrats only reluctantly entered the national government in March, and many are dismayed by what has happened since. In June, Merkel and Interior Minister Horst Seehofer — the leader of Bavaria's CSU party— feuded over whether to turn back small numbers of asylum-seekers at the German-Austrian border, briefly endangering the government.

Last month, the government wobbled again as the Social Democrats demanded the removal of Germany's domestic intelligence chief for appearing to downplay far-right violence against migrants. Coalition leaders agreed to move him to a new job after lengthy haggling that sapped the authority of Social Democrats' leader Nahles.

An electoral disaster in Hesse could endanger Nahles' job and embolden critics of the government to push for the Social Democrats to leave the federal coalition.

On the other side, a loss for Bouffier would make life more difficult for Merkel, who has indicated that she plans to seek another two-year term as CDU leader at a congress in December. The government's frailty has weakened her, as has the ouster of a close ally as leader of her party's parliamentary group.

"I think it's clear that this is her last term," Faas said. But a loss in Hesse could contribute to "the transition happening faster than she would perhaps want."

Seeking to bolster Bouffier, Merkel has recently pledged further action to head off driving bans on older diesel cars in some cities, including Frankfurt — another issue on which her government has failed to impress Germans. And she has warned her party to stop arguing about the 2015 influx of migrants to Germany, when Merkel kept the borders open against other conservatives' wishes.

"We have been far too preoccupied with ourselves," she said. "I demand that we now take care of the future."