Members of Starbucks Workers United staged their first strike in 13 months Friday and plan an escalating strike between now and Christmas Eve in what would become the union’s largest work stoppage since the organizing campaign started at the coffee retailer three years ago.

Workers at Starbucks stores plan to go on a five-day strike starting Friday to protest lack of progress in contract negotiations with the company. The strike, which would come a day after online retail giant Amazon was also hit by a walkout in the crucial final shopping days the season,