The battle over e-hail apps has pitted Mayor Bill de Blasio against one of his old fellow travelers.

De Blasio on Friday rebutted claims by the Rev. Al Sharpton that proposed legislation to cap the expansion of Uber and Lyft would leave minorities at the mercy of a racist yellow taxi industry.

In a speech last Sunday at the headquarters of his National Action Network—a group that has received financial support from the e-hail industry—the civil rights activist asserted the bills scheduled for a City Council vote Aug. 8 would make it harder for black and Hispanic New Yorkers to get for-hire vehicle service. Sharpton was a key supporter of the mayor's 2013 campaign.

De Blasio, in his weekly "Ask the Mayor" radio segment, highlighted recent city efforts to punish drivers who snub potential customers for racial reasons, including a new enforcement office within the Taxi and Limousine Commission. The mayor also cited the longstanding penalties drivers face for discrimination, which escalate quickly from a fine to a license suspension to revocation.

"I think there's a historic problem that's very real, and I don't accept any cab driver, for-hire vehicle driver, anyone discriminating against people of color," the mayor said. "That's a very real issue, but we have a lot of the right tools, and we're getting new tools working with the council."

De Blasio reiterated his support for the legislation, which would impose a one-year moratorium on new for-hire vehicle licenses (with an exception for wheelchair-accessible cars), and create a new category of TLC regulation for app-based companies that dispatch 10,000 or more trips daily. Less controversially, the council is also due to pass a measure that would instate a minimum pay scale for all app-hail drivers.

"One of the reasons is exactly why I ran for this office: to fight income inequality. Look what has happened to these drivers in the for-hire vehicle sector," the mayor remarked, citing a recent study by the University of California at Berkeley. "The overwhelming majority of these drivers are making subminimum wage. Because the business model of Uber in particular is to flood the zone with more and more vehicles, more and more drivers, grab market share, even if it means a lot of the drivers have no opportunity to make money."

But Sharpton argued that the city and its nonwhite citizens need to see the new enforcement office in action before restricting Uber and Lyft.

"If they are forming a bureau, they are conceding there is a problem," Sharpton told Crain's in a phone interview. "We should sit down and see how this new bureau works and how it will enforce, before you have a cap that would cut off service in many underserved neighborhoods, especially neighborhoods of color."

The at-times controversial activist also shrugged off suggestions that the financial assistance his nonprofit has received from Uber in any way influenced his views—and noted that both de Blasio and Council Speaker Corey Johnson have ties to the yellow-cab industry.

While Sharpton asserted that Johnson had received money from the taxi industry, upon further review, Crain's found no evidence of that in the speaker's campaign finance disclosures.

"I wouldn't say the mayor and Corey Johnson are nervous because they got money from taxi concerns," Sharpton said.