The Chicago Teachers Union has forged a coalition with a group of public-sector unions to “aggressively defend” against a “pension heist” by Illinois lawmakers at the request of Chicago Mayor Rahm Emanuel.

“We have been in negotiations with [Chicago Public Schools] for two years trying to figure out a way to do this and it’s always been clear to me they didn’t really want to solve the problem,” CTU President Karen Lewis said Wednesday. “They wanted Springfield to solve it and they wanted a political solution as opposed to a reasonable solution.”

CPS officials disagreed with the fiery labor leader.

“For the last two years, the District has been working to reach an agreement with CTU on meaningful pension reform that protects the retirement security of our teachers while avoiding dramatic cuts to the classroom. We have always been willing to sit down for discussions with the CTU,” CPS spokesman Joel Hood said in a statement.

Among the unions joining together are Chicago’s Fraternal Order of Police Lodge 7, the Chicago Firefighters Union Local 2 and the American Federation of State, County and Municipal Employees (AFSCME) Council 31, Lewis said. None could be reached for comment.

There’s also the Service Employees International Union (SEIU) Local 73, which counts some 6,000 CPS employees — special education including classroom assistants, security officers and bus aides — among its members.

“We want to come together as one and show a united front against unfair and unconstitutional pension reform,” SEIU spokesman Adam Rosen said.

Ald. Pat O’Connor (40th), Emanuel’s City Council floor leader, said it is neither a surprise nor a setback that unions representing city and CPS employees would band together in opposition to pension reform.

“Everybody fully expected they would want to work together to try and eliminate or limit the impact Springfield legislation would have on them. Their interests are not totally in sync. There is some divergence. But there’s enough commonality that it makes sense to work together,” he said.

Next year, state law requires the city to make a $600 million contribution to stabilize police and fire pension funds that now have assets to cover just 30.5 and 25 percent of their respective liabilities.

That will require a painful mix of new revenues and employee concessions that only the General Assembly can mandate.

Last Friday, the mayor held a 2.5-hour meeting with the Illinois House Speaker Michael Madigan and Senate President John Cullerton, both Chicago Democrats, to outline the magnitude of the problem and propose solutions.

Emanuel wants the General Assembly to impose annual property tax increases on Chicago homeowners and businesses, but put off the balloon payment to shore up police and fire pensions until 2023 to make the bitter pill easier to swallow.

He wants an General Assembly that has already solved the Chicago Park District’s pension problems to use that plan as a road map for other city unions.

And he wants lawmakers to impose the same pension reforms on Chicago teachers that they did on teachers in the suburbs and Downstate.

Emanuel’s office refused to discuss the pension plan outlined at Friday’s meeting, except to issue an email that said, “The Mayor regularly meets with the legislative leaders to discuss the city’s agenda in Springfield including pensions.”

Lewis said she will refuse to accept a deal like the one signed by Gov. Pat Quinn into law for the park district workers earlier this month.

Just because one city agency has made a pension deal doesn’t mean the CTU will fall in line, Lewis said. She stressed that CTU members don’t get Social Security.

“We know the mayor wants things the way he wants things but I’m not interested in trying to fulfill his dreams unless he’s interested in trying to fulfill mine,” she said.

In an interview after Wednesday’s State-of-the-State address, Cullerton said a solution to Chicago’s pension crisis is “a top priority” this session.

CPS’ Hood said CPS is working to “close a historic billion-dollar budget gap by reducing central office, administrative and operations spending.”

“We know that meaningful pension reform is part of the solution to bring financial stability to the district,” he said.

The CTU and members of the coalition will be in Springfield next month when Quinn delivers his budget address.

Contributing: Dave McKinney