German Social Demorat leader Martin Schulz
The ballot to elect a new regional parliament in one of Germany’s least populous states would normally have got little coverage outside its main city Saarbrücken.
But this year, ahead of Germany’s national election, it has generated intense interest in Berlin and beyond and observers see the vote as an early indication of how well the Schulz-revived Social Democrats (SPD) could do against Mrs Merkel’s Christian Democratic Union (CDU).
Mr Schulz, a former president of the European Parliament, suggested as much in his first speech after being made the party’s candidate.
Our plan is win elections
He told supporters: “Our plan is win elections. First in Saarland, then in Schleswig-Holstein, then in North Rhine-Westphalia, and eventually in the September national election.”
Since then, the so-called Schulz Effect has seen the SPD gain more than 10 percentage points in national polls, partly at the expense of Mrs Merkel’s CDU.
Martin Schulz faces his first real test as a serious challenger to Angela Merkel
Martin Schulz badges highlight the new SPD leader's growing popularity
The two parties are now virtually tied, with the SPD at 33 percent and the CDU at 32 percent, according to a recent Insa poll.
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And Merkel supporters fear defeat on Sunday could have a devastating knock-on effect when it comes to September’s national election.
Political science lecturer Hendrik Träger told politico.eu: “It would be a disastrous signal for the CDU to lose another one of the only four state premiers the party has left.”
Angela Merkel on the campaign trail with Annegret Kramp-Karrenbauer 'Merkel must go!' Protest in Dresden as Merkel arrives to celebrate German Unity Day Mon, October 3, 2016
Protesters jeered at German Chancellor Angela Merkel as she attended celebrations in Dresden to mark 26 years since Germany's reunification called German Unity Day.
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But Saarland’s Conservative state premier Annegret Kramp-Karrenbauer has been trying to downplay the link being made between local and national ballots.
She said: “The federal elections are being decided in September.
“Now, in March, it’s about our future. And we won’t have anyone else decide over it, no matter what their names are.”