Last year thousands of workers at China's largest sneaker factory, who makes over 300 million pairs of sneakers a year, or an estimated 1/5 of the world's athletic shoes, had gone on strike. Now, the protests are poised to intensify unless the factory is able to meet the workers' new demands.

After the initial strike at Yue Yuen Industrial Holdings, who makes products for Nike, adidas, Converse, and Puma among other brands, workers striked again this month and only returned to work last week, but they're still dissatisfied. Now, they've come up with a list of demands and threatened to stop work if their terms aren't met.

Demands include the addition of overtime to their "housing funds," or secondary pensions, as well as the restoration of yearly bonuses, which were once 20 percent of a worker's annual salary. Lastly, the protestors are seeking fair union representation, something that hasn't been possible with Yue Yuen's relentless grip on the industry.

While there's been little to no response from the brands who have sneakers produced by Yue Yuen, adidas did issue a statement. "None of the facilities manufacturing product for the adidas Group has been involved in the recent strikes," an adidas spokeswoman told Quartz.

Workers have marked today, March 31, as the deadline for Yue Yuen to meet their demands. If the factory isn't able to assuage them, tens of thousands of workers will once again go on strike, causing a rift not only in the Chinese economy, but the sneaker industry worldwide.

Don't go holding your breath on the next Jordan retro release. 

[via Quartz]