FRANKFURT, Germany - Polls are open in northern Germany for a local election that will test the strength of the country's Social Democrats as they try to deny Chancellor Angela Merkel a fourth term.
The Social Democrats are trying to hold onto power in Schleswig-Holstein, where they have governed since 2012. A good showing Sunday in the region with a population of 2.8 million would reinforce their prospects for challenging Merkel in the nationwide election in September.
Social Democratic governor Torsten Albig is defending a slim majority for his governing coalition with the Greens and the left-leaning SSW party, which represents the region's Danish minority. Polls point to a tight race with Merkel's Christian Democrats.
The Social Democrats surged in national polls after Martin Schulz, a former European Parliament president, was nominated as Merkel's challenger, but the party's ratings have since sagged.

The party currently plays second fiddle in a governing coalition headed by Merkel. Schulz has a chance to become chancellor if the Social Democrats come in ahead of Merkel — either by taking over top spot in the current right-left coalition, or by forming a coalition with other parties. (AP)