Updated 5:30 p.m. ET

Even though it has no employee unions, Wal-Mart (WMT) may get socked with worker strikes on Black Friday.

Workers want better pay, more health care coverage and permission to form unions without retaliation. If Wal-Mart doesn't offer them an olive branch, some of them appear ready to go on strike on one of the busiest shopping days of the year.

After days of downplaying the protests, Wal-Mart responded Friday by filing an unfair labor practice charge in the case. Wal-Mart shares closed Friday down 1% to $68.03.
The strikes seem to be coalescing around a group of current and former Wal-Mart workers called Organization United for Respect at Wal-Mart, or OUR Wal-Mart. The group is asking Wal-Mart employees to take the Black Friday pledge on its website and refuse to work on that day. The group is getting backing from the United Food and Commercial Workers union, known as UFCW.

Wal-Mart directly targeted UFCW Friday, asking the National Labor Relations Board to stop what it describes as illegal efforts to disrupt business, Reuters reports.

"We are taking this action now because we cannot allow the UFCW to continue to intentionally seek to create an environment that could directly and adversely impact our customers and associates," Wal-Mart spokesman David Tovar said in a statement. "If they do, they will be held accountable."

The union scoffed, and one spokeswoman described the company as "grasping at straws." OUR Wal-Mart says it has 1,000 protests lined up from now through Black Friday at Wal-Mart locations nationwide.

Many Wal-Mart employees earn less than $10 an hour, and the group is asking the company to bump up pay to at least $13 an hour, according to John Logan, a professor of labor and employment studies at San Francisco State University.

In addition, worker health care premiums are expected to rise as much as 36% next year, Reuters reports. Wal-Mart told Reuters that the average health care premium will only rise about 4.4% for employees, however, as some high-premium plans get removed. Wal-Mart pays for routine checkups, but employees need to meet a deductible of at least $1,750 before Wal-Mart begins paying 80% of the cost of doctor visits, tests and other services, Reuters reports.

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