"If in fact the chairman has indicated that he intends to do media ownership by December of this year, there is going to be a firestorm of protest, and I'm going to be carrying the wood," Dorgan declared. "We're going to have a big debate about this."

Dorgan learned of the timeframe from remarks that FCC Commissioner Robert McDowell, a Republican, made at a conference in Washington last week.

Dorgan discussed his opposition during a Commerce Committee hearing on oversight of the nation's digital television transition, another area of concern for Democrats and a growing cadre of Republicans.

The North Dakota senator publicly urged Senate Commerce Chairman Daniel Inouye, D-Hawaii, to hold hearings on the FCC's plans.

"I was flabbergasted yesterday to learn that there is now something under way that would end in December," Dorgan said.

FCC Commissioner Jonathan Adelstein, a Democrat, was on hand to testify about DTV and confirmed that FCC Chairman Kevin Martin, a Republican, wants the agency to consider proposed changes by Dec. 18.

"I'm not sure why the focus is on that date. To me, the issue is much more the substance of the matter than it is the process, because a lot of issues need to get [addressed] before we wrap this up," said Adelstein.

An FCC source said: "The date of Dec. 18 is just part of a proposal that the chairman is seeking consensus on...This has all been part of an open, transparent process. We've been leading up to this. We've been working on this for 18 months."

Martin, in an interview Wednesday with the Associated Press, confirmed the details of his plan for reaching a decision on the issue -- in which public comment on the proposed rules would open Nov. 13 in advance of the Dec. 18 vote.

Dorgan complained that new ownership rules are coming when the FCC hasn't finished examining "localism," -- the levels of local news and civic-minded programming that local stations air -- and whether digital TV broadcasters should take on new public-interest obligations.

There is not enough time by mid-December for citizens to have a fair opportunity to comment on these matters, he insisted.

"This is a big deal. We have way too much concentration of ownership in this country now," Dorgan said.

The FCC has been conducting field hearings, with a final localism session tentatively set for Oct. 31 in Washington and a final ownership hearing slated for Nov. 2 in Seattle, a Dorgan aide said. The agency source said the dates are not confirmed.

Dorgan pledged to prevent a repeat of 2003, when then-FCC Chairman Michael Powell, a Republican, pushed through a sweeping relaxation of the ownership rules on a party-line vote.

Under that plan, one entity could have potentially owned eight radio outlets, three television stations, the cable company and the main newspaper in a major market.

Martin, a commissioner at the time, supported the deregulation. But he says he is no longer comfortable with his vote on that plan, which was eventually invalidated by a federal appeals court.