Sporting a logo of the Comcast "C" devouring the NBC Peacock, Free Press was circulating an e-mail Wednesday calling on its members to ask their Senator to block the deal.
The e-mail linked to a form letter that could be easily fired off to Capitol Hill.
"Don't be silent on this issue," said the group, one of the deal's strongest critics. "With a few clicks, you can push back against Comcast.
The e-mail comes the day before Comcast chairman and CEO Brian Roberts is testifying before the Senate Commerce Committee about the proposed $30 billion joint venture.
Comcast is particularly interested in the NBCU studio product and cable channels, which Free Press said is particularly troubling. "The largest cable and Internet access provider could also control one of the nation's largest movie and TV studios. That's too much power for one company."
Comcast and NBCU argue it is a vertical deal that has relatively little overlap and with volunteered conditions that will protect access to broadcast and online content and increase program diversity.