In the race to succeed Mayor Michael Nutter, three front-runner candidates have managed to go months without much mudslinging. Besides a few swipes at public forums, there haven't been any negative campaign ads or other opposition material.

That ended Wednesday.

State Sen. Anthony Hardy Williams' campaign fired the opening salvo with an aggressive website that strongly suggests his opponents aren't the progressives they claim to be.

Leading with a banner that reads "The Real Progressive", the site progressivephilly.com features professionally designed pages where viewers can scroll through quotes from news articles outlining, for example, former Councilman Jim Kenney's checkered history on police brutality in the 1990s.

A much lengthier section accuses Lynne Abraham of defending crooked cops as district attorney and while working for private law firm Archer & Grenier.

The website does not directly say who the "real" progressive in the race is, leaving only a small logo reading "Paid for by Williams for Mayor" at the bottom of each page.

The Williams' campaign said it did not consider the website to be a form of negative campaigning, and that it was purely informational.

"The website is designed to present information about other the candidates that we think needs to be in the general conversation," said Barbara Grant, a spokesperson for Williams campaign.

But privately, sources close to Williams said they were frustrated that someone like Kenney had become the "darling of the progressive set" when he had "no kind of record on issues like poverty" while he served on council.

Whether or not the website is negative campaigning is relevant, because the Kenney campaign is treating it as such. But don't ask him, ask his friend, state Rep. Dwight Evans, who Kenney's campaign said would be responding on the former councilman's behalf.

"This website is nothing more or less than a disgraceful attempt to mislead voters and pit Philadelphians against one another," said Evans, who endorsed Kenney earlier this month. "Jim has been an advocate for improving community-police relations. It speaks very highly of Jim's record that you have to twist statements made two decades ago to create this mirage."

Former Councilwoman Marian Tasco, who also recently endorsed Kenney, released her own statement, saying the website proved Williams "is willing to stoop to new lows and divide our city in order to win."

Abraham also criticized the site, although her campaign declined to address the insinuation that she had repeatedly defended crooked police officers, choosing to instead talk about "the children."

"Tony Williams reiterated Jim Kenney's illegitimate attacks because they both want to distract the people of Philadelphia away from the real priority, our children. Williams and Kenney continue to fight over public schools vs. charters. Lynne thinks they're both wrong and, as Mayor, she will put all of our children first," a campaign spokesperson said in an email.