efe-epaMunich, Germany

Polling stations in Germany's southeastern state of Bavaria opened on Sunday to allow voters to begin casting their ballots in pivotal regional elections.

These elections are crucially important for the government of Chancellor Angela Merkel: some 9.5 million voters are set to pick a new regional government as polls suggest that Bavaria's Christian Social Union, an ally of Merkel's conservative bloc, could lose its absolute majority.

The Social Democratic Party (SPD), a partner in Merkel's federal government coalition, is also predicted to be deprived of its status as second force in the state and will likely be overtaken by the environmentalist Alliance '90/The Greens, who are projected to obtain around 19 percent of the ballots, while the SPD has been polling at around 12 percent.

The CSU – which has been the uncontested dominant force in conservative-leaning Bavaria since the 1960s – is set to earn around 33-35 percent of the vote, according to several polls, which would mark a record-low result for the right-wing party.

The outcome could even affect the coalition between Merkel's Christian Democratic Union, the CSU and the SPD, which was sealed in March after a long and laborious negotiating process.

Over the past few months, the alliance has undergone frequent crises and threats of rupture; the latter were mainly issued by the CSU's anti-immigration leader and federal interior minister, Horst Seehofer.

The polling stations are set to remain open until 6 pm local time.