Energy and Commerce Chairman John Dingell (Mich.) launched a wide-scale offensive Thursday to save his gavel from a surprise challenge by Oversight and Government Reform Chairman Henry Waxman (Calif.).

Meanwhile, sources said senior Democrats have been talking about the possibility of striking a deal to avert an embarrassing public showdown between the two Democratic titans, just as the party prepares to usher in a strengthened majority. Some Democrats suggested one option could be to promise Waxman the gavel in the next Congress if he backs down now — not a far-fetched proposal considering Dingell is 82.

Trying to bat down a claim from the Waxman camp that the California liberal had wrapped up enough support to seize the chairmanship, Dingell released a letter to colleagues laying out his plan to move aggressively on health care, climate change, and food and drug safety. And three panel members hopped on a hastily arranged late-afternoon conference call with reporters to make the case for their chairman, the longest-serving lawmaker in the chamber.

Rep. Mike Doyle (Pa.), one Dingell backer on the call, said when Waxman called him looking for support, Doyle asked him “rather pointedly” why Democrats should depose the current chairman. “And he was unable to give me a single reason why Dingell shouldn’t be chairman of the committee, other than he thought he would be a better chairman,” Doyle said.

Doyle, along with Reps. Bart Stupak (Mich.) and John Barrow (Ga.), made the case that Dingell deserves to stay put, both in a nod to the seniority system House Democrats have traditionally respected and because the 27-term lawmaker has a proven record of effective legislating. They said that based on their calls to other Members, including incoming freshmen, they believe the Waxman camp’s claim of having the race sewed up is inaccurate.

Dingell is counting on support from the more moderate wing of the Democratic Caucus, with leaders of the Blue Dog Coalition expected to mount a “significant effort” in his defense, a Democratic aide said.

But one member of that group, Rep. Jim Cooper (Tenn.), a fiscal conservative who has a long history of butting horns with Dingell dating back decades over health care and air quality issues, is whipping hard for Waxman, according to his spokesman.

“Cooper is a tremendous believer in Henry Waxman’s ability as a legislator,” Cooper spokesman John Spragens said.

Waxman is also relying on fellow Golden State colleagues in his bid, with Reps. George Miller and Howard Berman making calls on his behalf. Considering all three are home-state allies of Speaker Nancy Pelosi, and the fact that she and Dingell have a history of bad blood, speculation continued to run rampant about her role in the erupting battle.

Pelosi’s office remained quiet Thursday, even as she and Dingell huddled behind closed doors with executives of the Big Three automakers and the United Auto Workers to discuss the terms of industry aid that could be included in a stimulus package.

Meanwhile, the game of musical chairs in leadership ranks prompted by Democratic Caucus Chairman Rahm Emanuel’s (Ill.) decision to quit the chamber for a White House job next year got a new player. Rep. Marcy Kaptur (Ohio) plans to announce Friday she is declaring her candidacy for the Caucus vice chairmanship, being vacated by Rep. John Larson (Conn.), who is running to replace Emanuel.