A box from is pictured on the porch of a house in Golden, Colo., on July 23, 2008. Reuters/Rick Wilking

Up to 1,000 of, Inc.’s (NASDAQ:AMZN) employees in Germany could strike on Monday, at two separate locations, just before the busy holiday season.

“It lies completely in Amazon’s hands whether more strikes will take place in the upcoming Christmas season,” Mechthild Middeke told the Wall Street Journal. Middeke represents the German services union Ver.di, one of the largest unions in the world, with 2.1 million members from more than 1,000 professions.

The union called for strikes on Monday at Amazon’s Bad Hersfeld and Leipzig sites in Germany. The union is demanding that Amazon use industry-wide wage agreements for its German employees instead of sticking to Amazon-specific pay standards. Ver.di also wants Amazon’s German employees to be paid according to retail and mail order sector standards and not those of the logistics sector.

“Employees need an appropriate and reliable wage determined by collective agreement rather than by the employer alone,” Middeke said. The union is ready to negotiate whenever Amazon is, she added.

Amazon didn’t immediately comment. It has said in the past that its German workers earn salaries that are at the higher end of the pay scale of the German logistics sector. The company also issued a one-time payment of 400 euros to 600 euros ($542 to $813) for November.

It’s not the first time Amazon has faced strikes in Germany, and it likely won’t be the last. Ver.di promised further action, and it said that calm wouldn’t return until a collective wage agreement had been established.

In 2012, Amazon maintained internationally focused websites in the UK, Germany, France, Japan, Canada, China, Italy, Spain and Brazil, according to its 2012 annual report. It earned $8.7 billion in net sales in Germany in 2012, up from $5.2 billion in 2010. The company earned more in Germany in the past three years than it earned in Japan and the UK, and it has about 9,000 Germany-based employees.