The Philadelphia mayoral race has hit the airwaves, but not out of the effort of any individual candidate.

As first reported by Dave Davies of WHYY, Building a Better Pa., a labor-related Super PAC, sponsored the first ad of the race in support of former Democratic City Councilman Jim Kenney.

The 30-second spot, which aired Wednesday, dubbed Kenney “the right direction for Philadelphia.” It listed several positive actions Kenney performed during his time as a Councilman: protecting civil rights, lowering property taxes for senior citizens and the middle class, holding government accountable and creating jobs.

“For more than 20 years, he’s been one of Philadelphia’s most progressive voices,” the ad said of Kenney.

Kenney is not the first candidate to garner media support from Building a Better Pa. The super PAC came on the scene last year, investing in Democratic candidate Brendan Boyle’s primary campaign. Boyle won the four-way primary race and went on to win the 13th district seat.

According to filings, Building a Better Pa. receives a majority of its funds from the political committee of the International Brotherhood of Electrical Workers Local 98. That union is headed by the influential labor leader John Dougherty.

Building a Better Pa. is an independent expenditure-only committee, similar to the trio of Susquehanna executives supporting state Sen. Anthony Williams. The benefit of such committees is that they are not bound by the city’s campaign finance laws — meaning there are no limits on what they can spend on a candidate, as long as they don’t coordinate with him or her.

Kenney’s campaign attested to having no involvement with the ad, but that doesn’t mean it wasn’t supportive of its message.

“Jim has a long history of standing up for civil rights even when it wasn’t popular to do so, and the ad accurately reflects that as mayor he wouldn’t be a business as usual politician,” Kenney spokeswoman Lauren Hitt told WHYY Newsworks.

Another mayoral candidate, though, was less than pleased with the Kenney spot — and with independent expenditures in general.

Democratic candidate and former Philadelphia District Attorney Lynne Abraham circulated the “Philadelphia People’s Pledge” on Wednesday in an effort to limit outside spending in the Democratic primary.

Abraham’s goal is to keep Super PACs like Building a Better Pa. off the air. Her pledge proposes that candidates be required to pay 100 percent of the cost of any third-party ad, coordinated or independent, to the Philadelphia Public School System.

According to Abraham’s campaign, the pledge models one signed by Elizabeth Warren and Scott Brown during their 2012 Massachusetts Senate race.

“Philadelphians want and deserve a clean election, free of ‘dark money,’ outside spending, or attempts to evade campaign finance laws,” Abraham said in a statement. “‘Pay to Play’ has no place in our city or in this election.” The former District Attorney went on to emphasize her fight against corruption and special interests during her political career, promising to be “nobody’s Mayor but yours.”

“We must rescue our schools, create jobs, and reduce crime and poverty, but we cannot do any of those things if Super PACs and special interests are able to buy City Hall,” Abraham continued. “Philadelphia is not for sale.”

Abraham’s pledge has been hand delivered to every candidate on the ballot and is available to sign online, according to an email from her campaign.