City union workers say they’ve come up with a plan for Chicago to save $242 million by trimming middle management, working more efficiently and awarding fewer private contracts, thus eliminating the need for hundreds of layoffs that Mayor Rahm Emanuel has threatened.

The report released Tuesday by the Chicago Federation of Labor identifies $142 million in savings for the remainder of the budget year and for 2012. It said the city could likely find another $100 million, in savings as well. The bulk of the savings the union found would come from work efficiencies, such as standardizing city street lights and using apprentices to do trade work. The city could also save millions by reducing no-bid contracts to politically connected private companies, the report found.

The CFL says that would save more than the $10 to $12 million in savings Emanuel is looking for in order to close a budget gap that was left when a union concession agreement expired in June.  

“Look, the only thing we can do is take people at their word,” said CFL President Jorge Ramirez. “The mayor told us that if you can come up with ways to find efficiencies in government, to keep people from getting laid off, that he’s all ears.”

Emanuel’s administration inherited the labor dispute from former Mayor Richard Daley. The Daley administration balanced its 2011 budget, in part, by squeezing concessions and furlough days from unions. But that labor agreement expired last month, leaving the Emanuel administration to come up with about $31 million in savings to close out the budget year.

The mayor had been pushing for a menu of “archaic” work rule changes that he said could help close that gap, including cuts in overtime pay and to holidays and sick time. But for the most part, those changes were not part of the union proposal put forward on Tuesday.

A spokeswoman for Mayor Rahm Emanuel did respond to a request for comment.