Berlin’s creation of a minimum wage for postal services is the government’s worst policy mistake and Chancellor Angela Merkel is alone to blame for a “populist” drift in German politics, according to the leader of the country’s largest opposition party.

The “biggest danger is that this measure will destroy jobs”, Guido Westerwelle, chairman of the pro-market Free Democratic party, told the FT in an interview. But it would have political consequences too, he said, forcing politicians seeking re-election to campaign for higher wages.