Updated

A number of Republicans and some Democrats are considering a protest vote against Nancy Pelosi for House speaker when lawmakers convene Tuesday afternoon to launch the 111th Congress, FOX News has learned.

Once the House is sworn in, one of its first orders of business is to elect a speaker, a vote taken by the entire Congress.

The vote usually goes along party lines. Pelosi will run for the Democrats while Republicans were expected to nominate House Minority Leader John Boehner.

But some lawmakers of both parties are mulling a protest against their leaders and are considering casting their vote for the most senior member of the House, Rep. John Dingell, D-Mich.

Dingell first took office in 1955 and is the second-longest serving U.S. representative in history.

But Rep. John Larson, D-Conn., the fourth ranking member of the House Democratic leadership, predicted Pelosi would receive a unanimous vote from Democrats. Larson said that Pelosi has earned the respect of the conservative “Blue Dogâ€� Democrats who may be most inclined to cast a symbolic vote in protest of or in distance from Pelosi.

Still, House sources offered FOX News a number of reasons why some Democrats and Republicans might vote for Dingell.

Firstly, it would give moderate and conservative Democrats from marginal districts some political space between them and the more liberal Pelosi.

Secondly, many House moderates are upset that the House Democratic Caucus unceremoniously ousted Dingell from his chairmanship of the powerful Energy and Commerce Committee in favor of the more liberal Henry Waxman, a Pelosi disciple.

Thirdly, it would be highly unlikely for any Republicans to vote for Pelosi but some conservative Republicans have considered a protest vote against Boehner. He presided over two bloodbath elections for Republicans and while no GOPer has emerged as a strong enough alternative to be the minority leader, some might vote for Dingell as a clear statement of disapproval of Boehner.

Forging a coalition of conservative House Republicans with moderate Democrats could hold some potential to block Pelosi from the speakership, but chances of that scenario remain unlikely.

"That's not going to happen," said a senior Democratic aide when asked by FOX News about the odds of Pelosi losing the speakership on Tuesday.

Still, several GOP sources indicate that while no effort has been organized to draft Dingell, they expected the Michigan Democrat to score some votes.

Historically, only a couple of votes have deviated from each party's candidate during each new session's speaker tally, in part because those who vote against their party's candidate are often remembered by loyalists when a favor is needed down the road. The vote is by roll call.

When the Democrats were in the minority and Pelosi was the Democratic leader, Rep. Gene Taylor of Michigan made a practice of casting his vote for Democratic Rep. Jack Murtha of Pennsylvania. Taylor did vote for Pelosi as speaker in 2007.

When the full House votes for speaker, a reading clerk calls the names of each lawmaker. Lawmakers respond orally with the name of their preference. Some lawmakers opt instead to vote "present."

Ironically, the new speaker is traditionally sworn-in by the most-senior member of the House, in this case, Dingell.