CHICAGO (CBS) — A North Side alderman wants to scale back Mayor Emanuel’s $2-a-day “congestion fee” for parking in the city’s garages and lots, so that it only applies during weekday business hours when congestion is an issue.

Ald. Tom Tunney (44th) introduced the surprise ordinance at Wednesday’s City Council meeting, just weeks after Mayor Rahm Emanuel’s budget plan and $28 million “congestion fee” were unanimously approved by the aldermen.

Tunney said it doesn’t make sense to charge the congestion fee 24 hours a day, 7 days a week, when the city has invested millions of dollars in the theater district and is trying to encourage people to shop and dine downtown.

Tunney’s proposal would limit the congestion fee to drivers who enter parking garages and lots on weekdays from 6 a.m. to 6 p.m.

“It was originally billed as a congestion fee, but the ordinance that passed was not about congestion. It was about pricing. It was originally gonna be the Central Business District. Then, it became an issue of pricing no matter where it is. I want to get back to congestion,” said Tunney, owner of Ann Sather’s Restaurants.

“We shouldn’t be penalizing people when we’ve spent millions to encourage people to come downtown. We want congestion in the Loop on weekday nights and weekends. We want shoppers. We want families dining. We want people going to the theater and movies when the garages are half-empty.”

If approved, Tunney’s plan could poke an early hole in the city budget.

Emanuel wants to use the $28 million in expected revenue from the congestion fee to finance a CTA Green Line station near McCormick Place and express bus lanes linking commuter rail stations to Michigan Avenue and Navy Pier.

If they City Council approves Tunney’s plan to rein in the tax, the mayor’s ambitious plans might have to be scaled back.

But, the alderman said, “A lot of the revenue enhancements we put in the budget have some interesting assumptions. I don’t foresee this being a major revenue issue. I’d rather have people paying the sales tax and dining and shopping downtown.”

Emanuel spokeswoman Tarrah Cooper replied, “The proposal would create a budget deficit and we simply will not burden taxpayers in this way.”

(The Sun-Times Media Wire contributed to this report.)