Ina Fassbender/REUTERS Sharpa-Pei dog 'Pasha' (L) plays with a Golden Retriever

Corrections appended, Aug. 15 and 19

Over 9,500 people enter the DC Metro system via Union Station every weekday before 9:30 am. This month, incoming commuters were met by bright, mounted advertisements featuring perturbed-looking cats and dogs alongside phrases like “She’s pissed”, and “WTF?” Each read, “The Humane Society of the United States only gives 1% of its budget to local pet shelters.” Bearing the name HumaneWatch.org, this catchy campaign was only the latest low blow in a longstanding feud between the Center for Consumer Freedom and the Humane Society of the United States.

HumaneWatch.org is not an animal advocacy site. It is funded by the Center for Consumer Freedom (CCF), a nonprofit organization directed by Richard Berman, a notorious Washington public relations executive and former lobbyist. Founded with money from cigarette manufacturer Philip Morris in 1996, the CCF was originally created to promote smoker’s rights in the restaurant and hospitality industries. It has since expanded its causes to include the advancement of meat consumption, countering scientific evidence on the dangers of mercury and high fructose corn syrup, and a number of other unpopular crusades.

Richard Berman’s preferred method of campaigning is the creation of themed nonprofits and websites for each cause. Unionfacts.com attacks labor groups and encourages workers not to unionize; petakillsanimals.com attacks the animal rights group for euthanizing pets in its shelters; and thenewprohibition.com targets organizations like the American Medical Association and Mothers Against Drunk Driving for supporting a lower threshold for the legal blood alcohol concentration while driving.

The CCF’s campaign against the Humane Society began in early 2010 when HumaneWatch.org sponsored an ad in the New York Times claiming, “The dog-watchers need a watchdog.” In the following months, the group took out ad space in USA Today, Variety and The Wall Street Journal. “Sixty percent of the public believes that most of HSUS’s money is going to local shelters,” CCF Director Richard Berman told TIME. “My goal is to see to it that people who want to support pet shelter organizations give their money locally, and if they want to support the agenda of the Humane Society of the United States that they be fully apprised to the fact that that agenda is not about the local shelters.”

Eventually, however, the Humane Society started fighting back. In May 2010 the group sent an undercover journalist into Berman’s Washington public relations firm. “If charity does indeed begin at home, in the case of Richard Berman, it starts in a $3 million, 8,800-square-foot mansion he shares with his second wife in McLean, Va.,” reads the resulting report. The document quotes Naomi Seligman, formerly of the Center for Responsibility and Ethics in Washington, calling Berman “scum extraordinaire.” It also includes video clips of him leaving his office in a Bentley.

Just after the report was published, the Humane Society and Mothers Against Drunk Driving filed an unsuccessful complaint with the New York Commission on Public Integrity claiming that the American Beverage Institute—one of Berman’s nonprofits—was actually an unregistered lobbyist group. A few months later, HumaneWatch.org bought an ad in the New York Times saying that Wayne Pacelle, the Humane Society’s CEO, approved of Michael Vick owning a pet dog. In 2011, after Berman started an animal welfare charity called the “Humane Society for Shelter Pets,” Pacelle called him “the king of charity fraud” and a “Beltway con artist” in a blog post.

Berman told TIME that by the end of that year, he was fed up with the Humane Society’s personal attacks. On January 4, 2012, he sent a memorandum to the organization’s board threatening to sue for slander. “While the prospect of pursuing legal action against HSUS for Mr. Pacelle’s indefensible activities is something I wish to avoid, I reserve my right to pursue legal action should Mr. Pacelle continue to harass, defame, and libel me personally and my organization,” he wrote.

The Humane Society responded by filing an IRS complaint against the CCF in 2012, which still has not resulted in any action against Berman or his company. The complaint alleged that Berman used nonprofit laws to further the interests of his corporate clients. It also included evidence suggesting that most of the money in his charities went directly to his for-profit PR firm (hence, the $3 million house in McLean.)

Alan Heymann, the Humane Society’s Vice President of Communications, says that they believe the meat industry, which opposes the Humane Society’s vegetarian agenda and campaign against farm animal cruelty, is a primary supporter of the Center for Consumer Freedom. “It’s an organization that’s funded by those who benefit financially from keeping things the way they are for animals in the United States,” he told TIME. Berman says only a small portion of the CCF’s funding comes from agriculture companies. “Many of the companies and individuals who support the [CCF] financially have indicated that they want anonymity as contributors. They are reasonably apprehensive about privacy and safety in light of the violence and other forms of aggression some activists have adopted as a ‘game plan’ to impose their views, so we respect their wishes,” reads the CCF website. Contributors’ names are absent from the group’s 990 forms, which Berman has claimed protects them from opponents “with a violent side.”

Though his nonprofits’ financial statements may not be transparent, Berman’s affiliations are clear. He told TIME that a small amount of the funds he put into the film “Your Mommy Kills Animals”—which originally intended to discredit PETA—came from Hormel Foods. In 2012, Bloomberg News reported that Smithfield Foods Inc., a pork processor, hired him when they needed to stop a union uprising at a plant. Berman says he regularly consults with companies on labor issues because of his labor law background. Wendy’s International has admitted to supporting Berman at one point but does not reveal a current relationship. Nation’s Restaurant News called him “an industry Doberman” in 2007, and he writes a monthly column for them on policy issues of interest to restaurateurs.

“The HSUS agenda is designed to raise the cost of producing animal protein and to more or less encourage people to eat vegetables as opposed to eating ham or eggs or steak,” Berman told TIME. His website reads, “The Center for Consumer Freedom is working hard to protect your right to have the truth about the activists who threaten your favorite foods…We cannot guarantee that we will put these lunatics out of business, but outrage is a powerful thing. As more Americans learn the truth, the PETAs and Greenpeaces of the world might find it harder to make ends meet.”

It is a battle for the ages. “What in my mind you have here is the classic tale of a Washington industry lobbyist versus a large and influential advocacy organization,” said the Humane Society’s Heymann.

But the battle is hard to follow from a metro train car. As one of Humane Watch’s Union Station ads says, “Read the Fine Print.” In basic terms, the feud between the Center for Consumer Freedom and the Humane Society of the United States is no different from any other slash and burn fight between two political rivals. Except in this case, both sides get to use images of cute puppies wearing glasses.

A previous version of this article incorrectly stated that HumaneWatch.org paid for the Union Station advertisements. In fact, the CCF paid for them. It also misstated that the CCF’s causes included the advancement of trans fat use. The CCF’s trans fat project, which ended several years ago, criticized some tactics used to discourage trans fats; it did not promote their use. The article erroneously stated that the CCF represented the indoor tanning industry; it did not. The article also incorrectly suggested that the CCF paid for the websites unionfacts.com and thenewprohibition.com; those websites were created, respectively, by the Center for Union Facts and the American Beverage Institute, two different organizations directed by Berman, who was originally misidentified as a lobbyist. He has not been a registered lobbyist since 2005. The article also incorrectly described CREW as the Center for Responsibility and Ethics in Washington; it is Citizens for Responsibility and Ethics in Washington. TIME regrets the errors.