CHICAGO (CBS) — The Chicago Public Schools have struck a labor deal with their second largest union, but not the one that represents teachers.

The Service Employees International Union represents 5,500 janitors, school bus aides and security aides.

The new three-year contract includes wage increases and assurances that no more union jobs will be outsourced.

But CPS and Chicago teachers, who make up the largest union in the form the Chicago Teachers Union, remain far apart at the negotiating table.Teachers are planning a strike authorization vote for Wednesday.

CPS chief executive officer Jean-Claude Brizard took his case to the Fellowship Missionary Baptist Church on the city’s South Side.

“We know we also cannot afford some of the things that are being pushed – a 30 percent raise for teachers – we would love to be able to do that, but we know we can’t afford to do it,” Brizard said. “We’re looking at the funding gap that we had last year, the next coming year, and the years ahead – almost $3 billion in budget shortfall between last year and the next couple of years.”

A strike authorization vote would not necessarily mean there will be a strike. It would empower the union negotiating committee to call a strike if and when it so chooses.