Chicago Mayor Rahm Emanuel is taking heat from police unions as he looks for ways to cut tens of millions of dollars from the police budget, reports the Chicago Tribune.

The union has been critical of a plan put forward by Emanuel cutting vacancies in the police department.Currently, there are approximately 13,500 sworn officers for the Chicago Police Department, but there are always some vacancies at any time, the Tribune reports. By utilizing vacancies, Chicago government officials could make it seem as though more police on the streets did not impact the budget of the city.

But not everyone is buying into Emanuel's plan, most notably Mike Shields, the president of the Chicago Fraternal Order of Police.

Who are they kidding? Shields asked the Tribune. This is just a stunt. Clearly, they think Chicagoans are stupid.

This year, the city of Chicago faces a $635.7 million budget shortfall, which is expected to increase to $790 million by 2014 if significant changes are not made, the Chicago Sun-Times reports. This has led Emanuel to send out layoff notices to 630 employees already.

The revenue decline came from a diminishing population over the last ten years, the termination of one-time revenue boosters, and decreasing tax revenue due to the recession. Furthermore, Emanuel has been critical of his predecessor, Richard Daley, of running large deficits.

Last month, Emanuel vowed not to raise taxes, nor would he cut any police officers from the street, according to the Sun-Times. Furthermore, he would not impose additional one time revenue boosters, unlike Daley had. To balance the budget in his final year in office, Daley implemented new Skyway and parking meter fees, resulting in the collection of an additional $330 million.

Emanuel has also looked into cutting bureaucracy layers in the police department, the Tribune reports. Other plans floating around to balance the city budget include reducing garbage collection and plans for cities to compete with private contractors to provide services at lower prices.