By Richard Cowan
WASHINGTON (Reuters) -A proposal to create a 9/11-style commission to investigate the Jan. 6 U.S. Capitol attack by a mob of Donald Trump's supporters advanced in Congress on Tuesday even as one key Republican announced opposition and another suggested the former president could become a witness.
The Democratic-backed proposal won approval in the House of Representatives Rules Committee, setting up a planned vote in the full House on Wednesday. The party-line vote in the committee, with Democrats in favor and Republicans against, came hours after Kevin McCarthy, the top House Republican and a Trump ally, announced his opposition.
The measure faces uncertain prospects in the evenly divided Senate.
Trump's actions likely would be closely scrutinized in any commission investigation. Republican Senator Lisa Murkowski, asked during a CNN interview whether Trump should talk to the panel if it is created, said, "If you put together a commission that is focused on the events of Jan. 6, then I think he's obviously a very key individual."
The Rules Committee advanced a separate bill that would provide $1.9 billion in emergency funding for Capitol security, also opposed by Republicans.
Repudiating a deal on the commission announced last week by the top Democratic and Republican members of the House Homeland Security Committee, McCarthy said in a statement: "I cannot support this legislation."
House Speaker Nancy Pelosi, a Democrat, told reporters she was disappointed but not surprised over the "cowardice" shown by some Republicans "not to want to find the truth."
Hundreds of Trump supporters stormed the Capitol, interrupting the formal congressional certification of President Joe Biden's election victory, fighting with police and leaving five dead including a police officer. Trump and some other Republicans have sought to downplay the violence.
McCarthy complained that Democrats refused to broaden the scope of the planned commission to include 2020 protests in many U.S. cities against racism and police brutality and a 2017 shooting that seriously wounded congressman Steve Scalise, now the No. 2 House Republican, during a practice at a baseball field.
Neither of those incidents were related to the Jan. 6 violence. Representative Tom Cole, the Rules Committee's top Republican, said it would make sense to include investigations into other acts of "political violence."
The bill would establish a 10-member bipartisan commission to investigate the causes of the attack, security shortcomings and intelligence information. The panel would be directed to release a final report by Dec. 31. It would be similar to one that investigated the Sept. 11, 2001, attacks on the United States by al Qaeda militants and made sweeping recommendations.
The Capitol rampage came after Trump gave an incendiary speech to his followers, repeating his false claims of a stolen election. Trump, who was impeached afterward by the Democratic-led House on a charge of inciting insurrection, continues to falsely claim that last year's presidential election was marred by widespread fraud.
House Republicans last week ousted Representative Liz Cheney from their leadership for rejecting Trump's falsehoods.
Republicans also opposed the $1.9 billion bill that would help pay for costs related to the attack and improve security at the Capitol complex. Among their concerns were the price tag and a proposed new rapid-response force within the National Guard.
A seeming breakthrough came last week when legislation was announced giving Democrats and Republicans equal opportunity in choosing commission members and requiring that Democrats and Republicans on the panel approve witness subpoenas. Both were key demands being made by Republican leaders.
Some lawmakers revisited their memories of the attack during the debate over the commission.
"That day I crawled on my hands and knees in a gas mask" to seek safety, said Democratic Representative Norma Torres, who added that Capitol Hill workers "will carry the scars of that day for the rest of their lives."
(Reporting by Richard Cowan; Additional reporting by Susan Cornwell, Susan Heavey and David Morgan; Editing by Will Dunham and Scott Malone)