Updated: 8:01 p.m.

Momentum to grant budget autonomy to the District of Columbia is growing, and a new voice of support could help power the movement.

Sen. Joe Lieberman (I-Conn.) plans to introduce legislation that would sever the link between the District’s budget and the Congressional appropriations process, a senior Senate Democratic aide confirmed to Roll Call today.

Lieberman’s endorsement comes as support continues to build in the House, where Rep. Darrell Issa (R-Calif.), chairman of the D.C.-focused Oversight and Government Reform Committee, is spearheading the effort.

Issa’s support for freeing the District’s money from the control of federal lawmakers, who several times last year threatened to shut down city government as Congress neared stalemates on budget deals, has surprised D.C. budget autonomy proponents.

Traditionally, advocates for expanded D.C. rights mostly have been Democrats. But Issa is now joined by Majority Leader Eric Cantor (R-Va.) and Rep. Jo Ann Emerson (R-Mo.), chairwoman of the Appropriations subcommittee that oversees D.C.’s budget, in supporting the goal in principle and in looking for ways to achieve it. Virginia Gov. Bob McDonnell (R) has also endorsed D.C. budget autonomy.

Lieberman’s support, on the other hand, is not surprising. The chairman of the Senate Homeland Security and Governmental Affairs Committee with oversight over D.C. affairs has long been an ally of the District. Several times during the past decade, he introduced legislation to give D.C. representation in Congress.

However, people familiar with the issue agree that his coming out with a bill is a significant development.

“This is good timing, and this could be a part of Sen. Lieberman’s legacy,” said ex-Rep. Tom Davis (R-Va.), a former chairman of the Oversight and Government Reform Committee, about the lawmaker who will retire at the end of this session. “He could really help.”

While Issa said as recently as last month that he continues to explore avenues to advance D.C. budget autonomy legislation, he has yet to introduce a bill or specify where he might try to tack budget autonomy language onto existing legislation as an amendment.

He did introduce a measure last November but, arguing that it must be palatable to conservative House Members, included a provision barring the use of local funds to pay for abortions. After some deliberation, Del. Eleanor Holmes Norton (D-D.C.), D.C. Mayor Vincent Gray and others rejected the compromise, sending Issa back to the drawing board.

But while House support for budget autonomy appears to still hinge on abortion language, Lieberman’s bill will likely include no riders, according to DC Vote Executive Director Ilir Zherka. Lieberman could also move the measure through committee swiftly without such language, though its fate on the Senate floor is less certain.

Senate Homeland Security and Governmental Affairs ranking member Susan Collins (R-Maine) is reviewing the language, according to her spokeswoman.

Budget autonomy advocates are set to lobby lawmakers on Capitol Hill throughout today. DC Vote on Monday also released a poll it commissioned that shows 71 percent of Americans favor budget autonomy for the District.

Correction: April 16, 2012

An earlier version of this story incorrectly stated the language on abortion funding that is likely to appear in a House budget autonomy bill. The legislation would likely contain language banning local funding for abortion.