Trade union Verdi is calling on workers at Amazon's logistics centre in Leipzig to stop working from 0430 GMT, it said, after 600 workers at its facilities in Bad Hersfeld and around 300 in Leipzig went on strike on May 14.
Amazon employs around 9,000 people in Germany and has come under fire from the union for refusing to implement a collective agreement on employment conditions similar to deals at other mail order and retail firms.
The union is also pressing for higher basic pay and bigger supplements for night shifts.
In Leipzig, the union is calling for starting pay of 10.66 euros per hour, compared with 9.30 euros now. In Bad Hersfeld, it wants pay of 9.83 euros to be increased to 12.18.
Amazon said its workers' earnings were already at the upper end of what logistics companies pay in Germany. It said that it was willing to continue talks with Verdi but did not see a common basis for negotiations for now.