Trade union Verdi called for workers at a key Amazon logistics centre in Germany to go on strike over the crucial final shopping days before Christmas, demanding better pay and conditions for workers there.

Unions have staged repeated strikes in Germany, Amazon's second-largest market after the United States, since 2013, hoping to force the retail behemoth to recognise collective bargaining agreements that apply to other retail employees.

"Verdi wants to use the high-turnover days before Christmas to raise the pressure for collective wage bargaining at Amazon," the union said in a statement on Sunday, saying that staff Christmas bonuses should be quadrupled from their current level of 400 euros ($441). "It's precisely during Christmas business that colleagues are most heavily burdened, under stress and doing overtime, and that should be recognised with collectively agreed Christmas money," added Mechthild Middeke, leader of the strike.