David Cohen, executive vice president of the Comcast, testifies during a Senate Judiciary Committee hearing on Comcast's proposed merger with Time Warner Cable on Capitol Hill in April. (EPA/Michael Reynolds)

A group of consumer advocates and industry officials are banding together to warn lawmakers and regulators against letting Comcast buy Time Warner Cable. The group, which includes cable competitors such as Dish Network and trade groups representing Hollywood writers and musicians, plans to lobby the Federal Communications Commission and meet with members of Congress as the FCC considers whether to approve the $45 billion deal.

The Stop Mega Comcast Coalition argues that a merger between the nation's two biggest cable companies would give the combined entity too much control over broadband, television programming and advertising.

"To have a unified voice to connect the dots is something valuable as regulators conduct their ongoing, serious review of whether the merger is in the public interest," said Jeffrey Blum, a Dish policy executive.

The 16-member coalition brings together some of Comcast's most vocal opponents, but a number of key companies are notably absent from the organization. Among them are Netflix and Discovery Communications, whose criticism of the merger earlier this year prompted Comcast to fire back with frank accusations of "extortionate demands" on Discovery's part that took many observers by surprise.

Without the explicit backing of those influential players, the coalition may face difficulty gaining traction in Washington. But according to one advocacy group in the mix, who's in the organization matters less than the argument.

"Don't tell me that just because the other side has more lobbyists and lawyers, they'll win," said David Goodfriend, founder of the Sports Fan Coalition. "Facts win."

In a blog post Wednesday, Comcast spokeswoman Sena Fitzmaurice pointed to 600 comments filed to the FCC by politicians, chambers of commerce and others in support of the merger.

"There's no real news here," Fitzmaurice wrote, "a group of existing opponents making the same arguments they have already made and leveling essentially the same criticisms that have been leveled in the past, and weren’t found to be credible in our past transaction reviews."

The launch of the coalition coincides with an FCC decision Wednesday to continue accepting public feedback on the Comcast merger through Dec. 23.