CHICAGO (AP) — 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 will discuss the future of the effort that has spread to dozens of cities in less than two years.

About 1,300 workers are scheduled to 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.