WASHINGTON — In what many consider the best opportunity in years for Washington, D.C., to gain voting rights in Congress, Rep. Tom Davis, R-Va., introduced legislation Tuesday that would give district residents one seat in the House of Representatives — and Utah a fourth.

The bill attempts to break the political inertia and partisan squabbling that has stalled district voting rights for two centuries by giving Utah, a Republican bastion, an additional House seat to balance the seat for Washington, which is overwhelmingly Democratic.

Supporters of the measure, including the city's Democratic mayor and most of its Democratic-dominated council, hailed it as a pragmatic compromise, saying they would prefer full congressional representation — two seats in the Senate as well as one in the House — but were prepared to push Davis' bill as a first step.

"What we desire is what every citizen beyond our borders enjoys, the power to determine their future," said Mayor Anthony Williams.

But despite the show of bipartisan support, Davis' bill faces a Catch-22 of obstacles from both parties.

The Republican House majority leadership, which has opposed voting rights for the district for years, has told Davis that he must win broad bipartisan support for the bill before they will consider bringing it to the floor, Davis said.

But the House minority leader, Rep. Nancy Pelosi, D-Calif., has come out against the bill, saying it might allow the Republicans to increase their majority. She challenged the Republicans to bring the bill to a vote without Democratic support.

"Rep. Pelosi thinks that D.C. representation stands on its own merits," said Jennifer Cryder, a spokeswoman for the minority leader. "The Republicans are trying to play a shell game with it."

Under Davis' bill, the House would grow by two members to 437 after the November 2006 election. Washington would gain one seat, with the other going to the state next in line for a congressional seat, namely Utah, which narrowly missed gaining a fourth House seat after the last reapportionment.

Following the 2010 census, the House would shrink back to 435 members, with Washington retaining its seat and Utah likely to retain its additional seat because of population growth. Two seats would be lost in other states.

Pelosi's office said she opposes Davis' bill because it would require Utah to redraw its congressional lines before the 2010 Census. Because the Utah Legislature is dominated by Republicans, those lines would probably endanger the state's lone Democratic congressman, Rep. Jim Matheson of Salt Lake City.

Her concerns were echoed by Rep. Eleanor Holmes Norton, the District of Columbia's non-voting delegate to the House, who tepidly praised Davis for helping "raise awareness" but pointedly stayed away from his news conference.

Rep. Rob Bishop, R-Utah, who appeared with Davis on Tuesday, asserted the Utah Legislature drew unfavorable lines for Matheson before the last election, yet he still won with the largest margin in his three congressional contests.

"You can't draw it any more Republican," Bishop said.

Matheson's office did not return calls for comment. But Donald Dunn, the chairman of the Utah Democratic Party, said he was not opposed to Davis' bill, provided "Republicans don't try to be piggish and try to create yet another seat" for themselves.

House Speaker Dennis Hastert's office did not return calls for comment. Davis said Hastert, R-Ill., was "keeping his powder dry" on the bill until he could gauge its support in the Republican caucus. Davis added that Democratic opposition to the measure would provide an excuse for Republicans to let the bill die.

"That's why we've got to build critical mass from both parties," he said.

Washington's lack of congressional representation was one of the Founding Fathers' great pieces of unfinished business. Over the decades, a variety of proposals have been floated to resolve the problem, including returning the district to Maryland for voting purposes and granting it full statehood.

In 1978, Congress approved a constitutional amendment to give the district representation in both houses of Congress, but the measure did not come close to winning support from two-thirds of the states.

Davis' bill received mixed reaction from the district's many voting rights groups.

Walter Smith, executive director of DC Appleseed Center for Law and Justice, called the bill "ingenious," saying that "practical people" will support it "on the theory that Rome wasn't built in one day."

But Timothy Cooper, executive director of Worldrights, a human rights group, asserted that Davis' bill "could radically impede" the voting rights movement by muddling "our moral and legal cause.

"The fact that it will have taken 200 years to get a single vote in the House doesn't bode well for our prospects for achieving full voting rights any century soon," he said.