By Mike Dunn

PHILADELPHIA (CBS) — The first television ad of the 2015 Philadelphia mayoral race is now airing, but it was not paid for by the candidate who is being promoted.

“He’s been one of Philadelphia’s most progressive voices — he’s Jim Kenney,” an announcer intones in a 30-second television commercial now airing on some local stations, touting the candidacy of former city councilman Jim Kenney.

But the Kenney campaign did not pay for the commercial.  That was done by an independent political action committee called “Building a Better Pennsylvania.”

Lauren Hitt, spokesperson for Kenney, says the campaign welcomes the ad.

“While we want all the spending in this race to be as transparent as possible, we’re grateful that when a spot did come up, it was positive and highlights Jim’s record,” she said today.

The Building a Better Pennsylvania PAC has been tied to local labor unions and has previously runs ads in support of other Democrats in state legislative races.

These independent political committees are not bound to the same fundraising limits that the candidates themselves face.  Those limits on candidates are $2,900 from individuals and $11,500 from businesses and political committees.

And because money is tight for the six Democratic candidates, they are not expected to bust out their own TV and radio spots until they inch closer to the May 19th primary.