CHICAGO (STMW) — For the second time in a year, Mayor Rahm Emanuel is stepping in to block a ride-hailing giant whose investors include the mayor’s own brother from invading cabdrivers’ turf at O’Hare and Midway airports.

The Chicago Sun-Times reported this week that Uber has started an online petition drive tailored to persuade City Hall to let UberX drivers make airport pickups.

Uber spokesperson Brooke Anderson argued the move would help alleviate long lines of arriving airport passengers waiting for cabs and generate sorely needed revenue for the city because, like cabbies, UberX drivers would be required to purchase $4 in “airport departure stamps” for every pickup they make.

On Tuesday, City Hall slammed the door on the company’s request — at least for the time being.

“Last year the mayor passed a balanced set of regulations that have allowed ride-share companies to flourish in Chicago while protecting consumers,” mayoral spokesperson Elizabeth Langsdorf wrote in an email to the Sun-Times. “The administration is not planning to revisit those rules at this time — especially while the city continues to receive and investigate complaints about ride-share vehicles attempting to game the system.”

Langsdorf did not explain what she meant by attempting to “game the system,” but it might have something to do with tips circulating on social media on how to secure an UberX ride home from O’Hare or Midway.

It calls for ordering an UberX pickup just outside the airport zone, then calling drivers and asking them to come to the terminal. Drivers willing to break the rules “don’t help their cause,” one informant said.

An organization that’s trying to unionize Chicago cabdrivers applauded the mayor for acting quickly to prevent a company whose investors include Hollywood super-agent Ari Emanuel from siphoning even more business than it already has from cabdrivers.

“Even though the waits are very long, O’Hare is the place where we know we can make money. We’re not competing with a hidden fleet of private car, UberX drivers,” said Peter Enger, an official with the United Taxidrivers Community Council.

“We’ve already had plenty of money taken from us on the streets of Chicago. We can’t allow it at the airports.”

Enger said he’s forced to work “60 or 70 hours a week” just to cover his lease, gas and insurance expenses before turning a modest profit.

With no such overhead, UberX drivers, the overwhelmingly majority of whom work part time, can cherry-pick the busiest times.

“I work dead hours to get to busy hours and the only place I know I can make money is to buzz out to O’Hare at times when the wait time is less than an hour and pick up a $30 or $40 fare. To have that taken away would affect our family income and our ability to even stay in this industry,” he said.

It’s the second time in 15 months that Emanuel has stepped in to prevent UberX from invading what is the last bastion of protected turf for Chicago cabbies.

In May 2014, UberX sent a text and email to its drivers informing them of what appeared to be a change in city policy.

“IMPORTANT ANNOUNCEMENT: UberX partners will be able to pick up at O’Hare and Midway airports. . . . We hope that our UberX partners take advantage of this and we hope to see your number of requests increase!” the alert stated.

The UTCC got wind of the memo, sounded the alarm with the city’s Department of Business Affairs and Consumer Protection. City Hall stepped in to referee the dispute by ordering UberX to stop picking up passengers at O’Hare and Midway.

“The city has not authorized any ride-sharing company to offer pickups at either airport. Any company offering that service is subject to enforcement, which includes tickets and vehicle impoundment. The city intends to strictly enforce this policy,” Business Affairs and Consumer Protection spokesperson Mika Stambaugh wrote in an email to the Chicago Sun-Times.

UberX responded to the cease-and-desist order by saying, “At the request of the city, UberX partners are not currently picking up at either airport, despite both O’Hare and Midway desperately needing additional transportation options. We look forward to continuing our work with the city of Chicago to provide consumers with competitive, affordable and superior transportation choices.”

The issue of Uber making pickups at O’Hare and Midway keeps coming up because the mayor’s ride-hailing ordinance cracked the door open to airport entry. It required ride-hailing companies to service “all parts” of Chicago, not cherry-pick the downtown area and the city’s most lucrative neighborhoods.

They are prohibited from picking up street hails or riders at McCormick Place, O’Hare and Midway airports “unless the commissioner determines, in duly promulgated rules, following consultation with the commissioner of aviation, that such pickups can be accomplished in a manner that preserves security, public safety and the orderly flow of traffic; and . . . designated taxicab stands or loading zones.”

(Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)