The firm was founded by Jack Quinn, who served as counsel to President Bill Clinton from 1995 to 1997, and Ed Gillespie, a Republican Party strategist who served as the Republican National Committee chairman during the 2004 election cycle.
In February, New York-based Sirius said it would seek government approval to acquire Washington-based XM in a deal valued at $4.57 billion at the time.
But the companies face stiff opposition from federal lawmakers, who dispute the companies' claim that the merger would not eliminate competition nor lead to higher subscription prices.
The companies also face significant regulatory hurdles. In 1997, the Federal Communications Commission granted licenses to them on the condition that they would never merge to create a potential satellite radio monopoly.
Sirius Chief Executive Mel Karmazin has argued that, since then, new technology, such as high-definition radio, Internet-based radio and iPods, provide significant competition.
Both companies filed an application with the FCC to transfer radio licenses to a new combined company. However, the agency has not yet accepted the filing to begin a review that could take up to six months or longer.
In addition to Quinn and Gillespie, who are registered to lobby on behalf of the companies, several other veteran former Capitol Hill and White House officials are listed in the disclosure form.
They include: Jeff Connaughton, who worked as special assistant to the counsel to President Clinton in 1994 to 1995; Kevin D. Kayes, who most recently served as chief counsel to Senate Majority Leader Harry Reid, D-Nev.; Allison Giles, who served as chief of staff to the House Ways and Means Committee under then Chairman Bill Thomas, R-Calif.; Elizabeth Hogan, who worked as special assistant to the Commerce Department; and, Christopher McCannell, who was chief of staff to Rep. Joseph Crowley, D-N.Y.
Under a federal law enacted in 1995, lobbyists are required to disclose activities that could influence members of the executive and legislative branches. They must register with Congress within 45 days of being hired or engaging in lobbying.