By Olivia Marcus

WASHINGTON (MarketWatch) — When it comes to the battle over net neutrality, enemy lines seem to be linked to money.

“Campaign contributions don’t tell the whole story, but they tell a lot of the story,” said Bill Allison of the campaign finance watchdog Sunlight Foundation. “It’s been very effective to date in delaying or stopping net neutrality.”

House Oversight Committee Chairman Jason Chaffetz, a Utah Republican who last week opened an investigation that could stop net neutrality in its tracks, has received thousands of dollars in donations from net neutrality’s biggest corporate opponents.

In the last election cycle, Chaffetz accepted more than $15,000 from Comcast’s CMCSA, -0.80% political action committee, according to the nonprofit Center for Responsive Politics, which compiles campaign finance data at See OpenSecrets page on Chaffetz

That makes the cable company—the nation’s largest Internet service provider, which spent more than $14 million in anti-net neutrality lobbying in 2012—one of Chaffetz’s biggest contributors.

Comcast emphasizes that campaign contributions are part of the company’s business. “It is important for our customers, our employees and our shareholders that we participate in the political process,” said spokeswoman Sena Fitzmaurice. “The majority of our PAC contributions are to the senators and members who represent our employees and customers.”

Chaffetz’s press office did not respond to a request for comment.

Back in 2010 when the FCC first proposed net neutrality rules, similar opposition arose.

Rep. Marsha Blackburn, a Tennessee Republican said she would introduce legislation to overturn any regulations. In her career, she has received $62,500 from AT&T T, -0.82%  and $53,500 from Verizon Communications VZ, -0.83%   PACs—second and third respectively on her list of top contributors. See Blackburn’s top contributors

Former Sen. Kay Bailey Hutchison, a Texas Republican, said she would move to withdraw FCC funding to stop the agency from enacting the rules. Hutchison accepted almost $40,000 from AT&T’s PAC during her career.

On the other side of the aisle, more than 70 House Democrats sent a letter to the FCC warning the agency to halt its plans to reclassify broadband Internet service. Only four signers did not receive any monetary donations from telecommunications industry individuals or PACs, according to the Sunlight Foundation. Rep. Gene Green, a Texas Democrat, who led the campaign, has received more than $100,000 from AT&T’s PAC in his career. See Green’s top contributors

Blackburn’s spokesman and Green’s spokeswoman did not respond to requests for comment, but Verizon said it evaluates candidates’ existing views before giving money through its PAC.

“We support candidates who have laid out a pro-consumer, pro-innovation agenda,” Verizon spokesman Ed McFadden said.

As the FCC prepared to announce new rules this February, Republicans introduced draft legislation on the issue. The bill would bar the FCC from reclassifying broadband as a Title II common carrier, a regulatory move cable companies have long opposed.

“We also hope that proponents of Title II will consider that any FCC action taken on a partisan vote can be undone by a future commission in similar fashion, or may be declared invalid by the courts,” said Jim Cicconi, AT&T’s senior executive vice president of external and legislative affairs.

Two of the congressmen who worked on the bill, Rep. Fred Upton, a Michigan Republican, and Rep. Greg Walden, an Oregon Republican, have received large sums from the cable industry.

Comcast, AT&T Inc. and Verizon are all on their lists of top contributors. Walden has accepted a total of $217,250 from the three companies in his career. Upton has received even more: $309,500.

Spokesmen for Walden and Upton did not respond to requests for comment.

It is no secret that money can play a heavy hand in Washington. But what makes the net neutrality battle different, Allison said, is the sheer imbalance of the fight.

Verizon, AT&T and Comcast have lobbied about three times as hard as lobbyists on the other side, according to a report from the Sunlight Foundation.

The report found that anti-neutrality organizations outspent pro-neutrality organizations by a five-to-one margin. Out of the five organizations that spent the most money lobbying on net neutrality in 2012, four were anti-neutrality. They dished out a combined total of more than $66 million.

“When you’re looking at the two sides, if there’s one that has a much more significant interest and is putting much more intensity into the campaigning, then that’s probably going to be more decisive than the side that is lobbying on that and 15 other things,” Allison said.

The FCC will vote on Chairman Tom Wheeler’s proposed regulations at the end of the month, but the net neutrality debate is far from over.

“It’s sort of the interstate highway system of the 21st century,” Allison said. “Who’s going to control it, what kinds of rules there are going to be… those become critical questions, and it effects almost everybody.”