Updated

Fast food workers say they're prepared to escalate their campaign for higher wages and union representation, starting with a national convention in suburban Chicago where more than 1,000 workers are expected to discuss the future of the effort that has spread to dozens of cities in less than two years.

About 1,300 workers will attend sessions Friday and Saturday at an expo center in Villa Park, Illinois, where they'll be asked to do "whatever it takes" to win $15-an-hour wages and a union, said Kendall Fells, organizing director of the national effort and a representative of the Service Employees International Union.

The union has been providing financial and organizational support to the fast-food protests that began in late 2012 in New York City and have included daylong strikes and a protest outside this year's McDonald's Corp. shareholder meeting that resulted in more than 130 arrests.

"We want to talk about building leadership, power and doing whatever it takes depending on what city they're in and what the moment calls for," said Fells, adding that the ramped-up actions will be "more high profile" and could include everything from civil disobedience to intensified efforts to organize workers.

"I personally think we need to get more workers involved and shut these businesses down until they listen to us," perhaps even by occupying the restaurants, said Cherri Delisline, a 27-year-old single mother from Charleston, South Carolina, who has worked at McDonald's for 10 years and makes $7.35 an hour.

Delisline said she and her four girls live with her mother, but the family still has difficulty paying utilities and the mortgage while providing for her children. She said she has not been to a doctor in two years and does not get paid if she stays home sick.

"To have a livable wage, it's going to need to be $15 an hour," said Delisline.  "We make the owners enough money that they have houses and cars and their kids are taken care of. Why don't (they) make sure I can be able to do the same for my kids and my family?" she said.

The campaign comes as President Barack Obama and many other Democrats across the country have attempted to make a campaign issue out of their call to increase the federal and state minimum wages.

The current federal minimum wage of $7.25 an hour translates to about $15,000 a year for someone working 40 hours a week, though many fast-food workers get far fewer hours. Obama and others have called for increasing it to $10.10.

Fast food workers say even that's not enough because most people working in the industry now are adults with children, rather than teenagers earning pocket money. The restaurant industry has argued that a $15 hourly wage could lead to business closings and job cuts.

A McDonald's spokeswoman did not return a message seeking comment.

But the National Restaurant Association said Thursday that increasing wages to $15 will not solve income inequality and that the campaign was an attempt by unions to boost dwindling membership.

"Instead of demonizing an industry that opens doors for workers of all ages, backgrounds and skill levels, the focus should be on finding better solutions to lift individuals out of poverty," including policies that increase education and job training, said Scott DeFife, the association's executive vice president of policy and government affairs.

Turnout for the protests has varied, but they've struck a chord at a time when the gap between the country's rich and poor has widened. Executive pay packages also are coming under greater scrutiny, including that of McDonald's CEO Don Thompson, who was given a pay package worth $9.5 million last year. Nevertheless, shareholders this year overwhelmingly voted in favor of McDonald's executive compensation practices.

Nancy Salgado of Chicago said she and her two children share a bedroom after being forced to move into an apartment with two other adults after her hours at McDonald's were cut from 40 a week to about 24.

"I don't think $15 will make me rich. ... I just want an apartment for my family and be able to have my kids in their own room, to not have to wait for the washing machine or the bathtub, and I don't want to be behind on bills if I take time off or get sick," said Salgado, who earns minimum wage after 12 years with the company.

"If we've got to stop working and shut down (restaurants) to get it, that's what we're going to do," she said.