Dozens of Republicans have defied their party leaders and Donald Trump to back a commission to investigate the Capitol riot.
The former president had urged Republicans to vote against the “trap,” but 35 went against him and sided with Democrats by 252-175 to establish the commission.
All 10 of the House Republicans who voted to impeach Trump in January for incitement of insurrection were among those who voted for the commission, reported the BBC.
The inquiry, which will establish a 10-member body, will resemble the commission that investigated the 9/11 attacks on New York and Washington.
The body will make recommendations by the end of the year on how to prevent any repeat of the Capitol invasion.
But Democrats face an uphill fight getting the bill through the Senate, where they will need at least 10 Republican "yes" votes to prevail.
New York congressman John Katko, who negotiated the legislation with Democrats, said: “This is about facts - it’s not partisan politics.”
Mr Katko added: “The American people and the Capitol Police deserve answers, and action as soon as possible to ensure that nothing like this ever happens again”.
But Marjorie Taylor Greene, a Georgia Republican, said the commission was a ruse by the Democrats “to smear Trump supporters.”
The debate on whether an inquiry should be established comes four months after pro-Trump supporters stormed into the Capitol, breaking through barricades to roam the halls and ransack the historic building.
