WASHINGTON - House Republicans on Wednesday moved toward an election-year special investigation of the deadly attack on a U.S. diplomatic post in Libya, brushing aside Democratic concerns over the panel's scope and composition. The Obama administration, meanwhile, accused Republicans of "political motivation" after they issued a fund-raising e-mail linked to the Benghazi probe.

Ahead of a Thursday vote to approve the establishment of the Benghazi select committee, House Speaker John A. Boehner (R., Ohio) vowed that the examination would be "all about getting to the truth" of the Obama administration's response to the attack and not be a partisan, election-year circus. "This is a serious investigation," he said, accusing the president and his team of withholding the true story of how militants killed Ambassador Christopher Stevens and three other Americans on Sept. 11, 2012.

Dems consider boycott

Democrats pondered a boycott while waiting for Boehner to respond to a demand from Minority Leader Nancy Pelosi that he scrap his plan for a committee of seven Republicans and five Democrats. Democrats insisted membership should be evenly split, and urged time and cost constraints for a forum they likened to a "kangaroo court" designed only to drum up GOP support ahead of the November elections.

Under Boehner's legislation, the select panel "can go on forever," Rep. Xavier Becerra (D., Calif.) told reporters. "The amount of money they can spend is undefined and can be unlimited."

A bipartisan stamp?

The committee's establishment is assured in the GOP-run House. But Republicans, too, expressed an interest in securing Democratic participation. They've made Benghazi a central plank of their strategy to wrest control of the Senate from the Democrats later this year. An inquiry that can be presented as bipartisan would have greater credibility with voters beyond the conservative base.

Republicans insist the White House, concerned primarily with protecting President Obama in the final weeks of his reelection campaign, misled the nation by playing down intelligence suggesting Benghazi was a major, al-Qaeda-linked terrorist attack. They accuse the administration of stonewalling congressional investigators ever since, pointing specifically to e-mails written by U.S. officials in the days after the attack but only released last week.

"A line was crossed," said Boehner, who in April said there was no need for a select committee.