Chicago - 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 this weekend at an expo center in Villa Park, Ill., 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, S.C., 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?"

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.

The workers say even that's not enough because most people working in the industry now are adults with children, rather than teenagers. 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 $15 will not solve income inequality and that the campaign was an attempt by unions to boost dwindling membership.