Incumbent David McAllister, of Chancellor Angela Merkel's center-right alliance Christian Democratic Union, is running against Stephan Weil of the Social Democrat Party, in what has been a tight race, Euronews reported.
Merkel, who is up for reelection in September, has been campaigning in Lower Saxony on behalf of McAllister.
In September, Merkel will face off against challenger Peer Steinbruck, of the SPD, Voice of America reported.
Merkel is seeking a third term.
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