The campaign to get fast-food workers paid at least $15 a hour resumes later this week.

Union organizers say workers will walk off their jobs Thursday in 150 cities nationwide. Restaurants that they say will be affected include McDonald's (MCD), Burger King (BKW) , Wendy's and KFC, which is owned by Yum Brands (YUM).

The action would be the latest in a two-year effort to get employers to pay them a minimum wage of $15 an hour and allow them to form unions without retaliation.

Nancy Salgado, a 27 year old single mother of a 3 year old boy and an 8 year old girl, plans to strike.

Salgado works at a McDonald's in the Logan Square area of Chicago earning $8.25 an hour, or about $600 a month take home pay.

After splitting rent and utilities with 3 roommates, and paying for child care, she's left with a little over $100 a month for food and everything else.

"If I have a dollar at the end of the month it's a miracle," Salgado said.

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Currently, the median pay for fast-food workers is just over $9 an hour, or about $18,500 a year. That's roughly $4,500 lower than the Census Bureau's poverty threshold level of $23,000 for a family of four.

Thursday's action would come more than a month after the National Labor Relations Board's general counsel ruled that McDonald's is a joint employer that exerts substantial power over working conditions at its franchisees. The ruling, if upheld, means McDonald's could be held liable for labor violations at its more than 12,000 franchisee-owned restaurants.

McDonald's has contended that franchisees operate as independent businesses and that, therefore, it's not liable.

In March, McDonald's workers filed seven class-action lawsuits in New York, California and Michigan over wage theft violations. The suits allege that McDonald's has forced employees to work off the clock, not paid them overtime and struck hours off their time cards.

McDonald's did not respond to a request for comment on the status of the class action suits or the preliminary ruling by the National Labor Relations Board.

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Union organizers say the movement has elevated the debate about inequality in the U.S. and helped raise the minimum wage in some states, including Connecticut and New Jersey.

Public policy group Demos says CEO compensation in the industry since 2000 quadrupled to $24 million, while the average fast-food worker's wage only increased 0.3%. Fast-food CEOs make 1,000 times more than the average worker in the industry, according to Demos.

U.S. census data show that the face of the fast-food worker has changed dramatically over the years. Workers over the age of 20 now make up 70% of the workforce and nearly 40% have children. A third of them have spent some time in college.

Salgado, who didn't finish high school, said she'll do whatever she has to to win the fight for a $15 minimum wage and a union.

"My 8 year old daughter tells me 'Everything is OK mommy,' and I tell her, 'yes,'" said Salgado. "But when she goes to sleep I know it's not OK."