Updated

Democratic lawmakers weighing whether to participate in a special investigative committee on the Benghazi attacks should name just one lawmaker to the panel, rather than boycott the investigation altogether, a top lawmaker said Thursday.

Rep. Rosa DeLauro, D-Conn., sent a letter to Democrats meeting on Friday to discuss how to respond to the committee approved Thursday by the GOP-led House in a vote largely on party lines, The Washington Examiner reported.

DeLauro, co-chairs the Democratic Steering Policy Committee, which creates committee assignments, told her colleagues that boycotting the panel "would leave our caucus with no voice to engage in committee proceedings."

Instead, appointing a single member would allow Democrats to participate in the "partisan committee" and access important material, she said.

"Such a participant could maintain Democratic access to committee proceedings and material, question witnesses, monitor the House Majority's activities and provide a powerful voice to raise issues and make appropriate public comments," DeLauro wrote.

Some rank-and-file members argue that by joining the select committee, they'd be improperly legitimizing what they view as a political effort. Others, though, argue that if they don't participate, they will not be able to shape the direction and narrative of the probe.

The House voted 232-186 to approve the panel. The vote breakdown was 225 Republicans and 7 Democrats in favor, with 186 Democrats voting against the measure. The Democrats who backed the probe were all moderate to conservative party members who face tough re-election campaigns.

"This doesn't need to be, shouldn't be and will not be a partisan process," House Speaker John Boehner, R-Ohio, said in a speech on the House floor promising pursuit of the truth.

Democrats have their doubts.

"It's hard to trust what Speaker Boehner is doing with this new select committee," Rep. Xavier Becerra, D-Calif., chairman of the House Democratic Caucus, said in a statement after the vote. He pointed to Boehner's comments a month ago that a special panel was unnecessary.

After the vote, Minority Leader Nancy Pelosi, D-Calif., was noncommittal about whether Democrats would participate on the special committee, but assailed the new probe. "Our nation deserves better than yet another deeply partisan and political review," she said.

Boehner's legislation creates the special committee through the end of the year. It will have to be reapproved when a new Congress begins in January or go out of existence. The select committee has no explicit financial constraints. The speaker was expected to announce the Republican members on Friday.

Rep. Trey Gowdy, R-S.C., who will head the panel, said, “This resolution equips the select committee with the scope and tools necessary for the seriousness of this investigation. We are charged with a clear mission: uncover all the facts and provide answers to the American public."

House Democrats have issued several demands if they are to participate in the select committee. Boehner already has rejected their call for equal representation on the panel, deciding instead to fill it with seven Republicans and five Democrats. The Democrats also seek guarantees they'll have equal access to documents, say on subpoenas and right to question witnesses.

Republicans have defended the structure of the committee, noting that a prior select committee under the previous Democratic majority had nine Democrats and six Republicans.

Among other priorities, the committee will seek to answer what was done in response to the Sep. 11, 2012 attack, including efforts to rescue U.S. personnel. Four Americans, including Ambassador Chris Stevens, died in the assault on the U.S. compound.

The Associated Press contributed to this report.