Angela Merkel's conservatives appear set for a thrashing in a state vote this weekend — the first in a string of tests crowding the German chancellor's agenda at a difficult time for Europe.

But the betting is that Merkel will emerge from a bumpy ride with her grip on the continent's biggest economy still firm.

Polls suggest the opposition Social Democrats will win back Hamburg, a stronghold in the past, by a wide margin in a regional election Sunday after a decade of rule by Merkel's Christian Democrats.

Opposition leader Sigmar Gabriel says he expects an "excellent result" in Hamburg. Merkel says her party's situation there is "not easy" after a series of local setbacks.