(CBS) — With a huge budget deficit ahead, Chicago city government is desperately searching for new income.

Now, Mayor Rahm Emanuel may be seriously considering an income tax.

CBS 2’s Derrick Blakley takes a look at the smoke signals from city hall.

Emanuel isn’t specifically talking income tax yet. But one of his strongest city council allies, 49th Ward Ald. Joe Moore, is speaking up.

“In my ideal scenario, it would be a graduated income tax that would be pegged at peoples’ ability to pay,” he says.

Some of the biggest U.S. cities already tax wages, including New York, Philadelphia, Detroit, Cleveland, San Francisco and Denver.

The tax that would also strike suburbanites who work in the city, Moore says.

The concept drew support Thursday from other mayoral allies who want to avoid a property tax hike.

“We should spread the pain across the city,” Ward 27 Ald. Walter Burnett says.

Last year, the mayor rejected a city income tax. Not Thursday.

“Mayor Emanuel appreciates the alderman’s suggestion because the problem we face is a big one,” a spokesperson says.

The most liberal aldermen, like newly-elected Carlos Rosa, favor something else altogether: a tax on trades at Chicago’s financial exchanges.

“We also need to ask the rich to pay their fair share,” he says.

Moore denies he’s sending up a trial balloon, testing the waters for Mayor Emanuel. But no one at City Hall denies the search for new revenue is real.

Four years ago, a study by Chicago’s inspector general found that a flat-rate, 1 percent city income tax would generate $500 million.