But Alke Boessiger, head of commerce at UNI Global Union, which has coordinated the talks along with the International Transport Workers' Federation, accused Amazon of treating workers "like robots".
The unions at the meeting are planning to develop a coordinated strategy to increase wages and improve working conditions. They also hope to increase worker representation across Europe – especially in Poland and the Czech Republic, where the company is planning to open more distribution centers.
Amazon, however, said it "firmly believed" the best way to understand and respond to its workforce was directly with its employees.
"We have multiple avenues to listen to and respond to our associates, including employee surveys, anonymous helplines, voice of associate boards, All Hands meetings, roundtables, and other mechanisms," the company said in a statement emailed to CNBC.
Amazon has already been hit with a number of strikes by workers across Europe. In Germany –where the retailer employs around 9,000 people – workers' efforts to negotiate new pay deals have resulted in multiple strikes. The company has also been hit by industrial action in France and protests in Britain.
It follows a public backlash against the U.S. company for channeling its European revenues to Luxemburg in an effort to minimize corporate tax payments. For example, Amazon reported sales of $7.3 billion in Britain in 2013, but only paid £10 million ($17.2 million) in tax, according to Reuters.