MADRID (Reuters) - Workers at Amazon’s biggest warehouse in Spain started a two-day strike on Thursday just ahead of a gift-giving feast day, as part of a long-running campaign for better pay and conditions.

The strike, called by the country’s two main unions, CCOO and UGT, may affect the delivery of products for Epiphany, the day on which three kings brought gifts to Jesus in Christian tradition, which most Spaniards mark by exchanging presents.

“We have been protesting for a year. This is the richest company in the world and they want to keep profiting by taking away workers’ rights,” said David Matarraz, an Amazon worker outside the warehouse close to Madrid.

Amazon workers in Germany and Poland have also walked off the job, demanding better conditions.

German and Spanish workers went on strike two months ago on Black Friday, the discount spending spree that kicks off the Christmas shopping season, but Amazon said this had no impact on customer orders.

Seventy percent of employees at the Spanish center joined Thursday’s strike, CCOO representative Douglas Harper said. An Amazon spokesman denied this, saying most employees at the center had been at work on Thursday.

Employees at the Madrid center earn a minimum 19,300 euros ($21,933) per year, the spokesman said. Spain’s legal monthly minimum wage is 1,050 euros.

Protesters at the site lit a bonfire and a man walked around wearing a mask showing the face of Amazon CEO Jeff Bezos.