As the ballots went out in the special election for Congress, Colleen Hanabusa launched the first attack ad against fellow Democrat Ed Case, challenging his record during his previous term in Washington.

“;Case voted to extend Bush tax cuts for the wealthy that caused skyrocketing deficits, voted against prescription drug coverage and even considered changing Social Security to reduce benefits,”; a voice-over says in the TV spot.

The ad began airing this week as roughly 316,000 ballots were mailed yesterday to voters in the 1st Congressional District, stretching from urban Honolulu to Mililani. The deadline to return ballots is May 22.

Case, who previously represented the 2nd Congressional District from 2002-06, said he expects ads against him to heat up as the voting begins, “;because they both view me as their main threat.”;

“;Colleen's attack ad is still another example of the lack of credibility that has been the hallmark of her campaign and reflects a desperate campaign dropping fast,”; he added.

Hanabusa's campaign stood by the ad.

“;This television commercial is a factual comparative ad that is based on Ed Case's past voting record and stated positions on the issues,”; campaign spokeswoman Crystal Kua said.

National Democrats continued their Case-Hanabusa neutrality stance, instead launching a new attack ad against Republican Charles Djou. Democrats also called out Djou for what they call his hypocrisy for accepting contributions from top congressional Republicans as reports surfaced of his benefit from a behind-the-scenes effort in Washington, D.C.

Djou, meanwhile, called on supporters to get out the vote.

“;The national Democrats know this race is important and have shown it by spending over a quarter of a million dollars on completely FALSE ads about me and my record,”; Djou wrote in a message to supporters.

But Djou also benefited from an infusion of campaign cash from mainland donors, according to an online report. The Washington-based website Politico reported an “;under-the-radar”; effort organized by top congressional Republicans—including Minority Leader John Boehner, Minority Whip Eric Cantor and National Republican Campaign Committee Chairman Pete Sessions—raised more than $100,000 from about 40 GOP members.

Djou, meanwhile, is seeking to capitalize on Thursday's state House vote to legalize same-sex civil unions. In a statement after the House vote, he said Hanabusa, the state Senate president, had “;blatantly ignored the will”; of Hawaii residents by supporting civil unions.

Dylan Nonaka, Djou's campaign manager, said the intensity among Djou supporters will rise in the wake of the bill's passage, even though Congress will have no say in whether Hawaii adopts civil unions.

In a statement, Hanabusa said she is proud of her record “;on civil rights and equality. It is a shame that Charles Djou has chosen to capitalize on this issue for his own political gain and to further divide our community instead of bringing people together.”;

She and Case support civil unions, but she backs the state's ban on same-sex marriage. Case has long opposed the prohibition.

The Associated Press contributed to this report.