Martin Schulz gives a press conference at the SPD headquarters | Odd Andersen/AFP via Getty Images Martin Schulz gives German socialists poll boost If voters could directly pick their chancellor, they’d go for Schulz over Merkel.

Martin Schulz being named the German Social Democrats' candidate for chancellor helped the party to its highest approval rating since 2013, according to an opinion poll.

The poll by broadcaster ARD, published Thursday, suggests that SPD would receive 28 percent of the vote — up from 20 percent in a poll a month earlier. The Christian Democrats (CDU) of Chancellor Angela Merkel were on 34 percent of the vote. Germans go to the polls on September 24.

The poll also suggests that if voters could directly pick their chancellor, which they cannot, they would choose Schulz over Merkel. Half of respondents said they would vote for the SPD candidate, compared to 34 percent who said they would back Merkel, down from 41 percent last month.

Half of respondents say they would like to see an SPD-led government after the election, with 39 percent saying they want a government to be led by the CDU.