The Democratic-controlled US House voted mostly along party lines on Wednesday to create a select committee to probe the deadly attack on Capitol Hill on 6 January.

The final vote was 222-190, with only two Republicans representatives, Liz Cheney of Wyoming and Adam Kinzinger of Illinois joining all Democrats to back the new committee.

House Democrats, whose majority in the chamber led to a vote that impeached then President Donald Trump exactly one week after the 6 January insurrection, moved to establish the select committee after legislation to create an independent bipartisan commission was blocked by Senate Republicans last month.

“We have a duty to the Constitution and to the American people to find the truth of 6 January, and to ensure that such an assault on our democracy can never happen again,” House Speaker Nancy Pelosi said.

The select committee is tasked with investigating and reporting on the basis of “the facts, circumstances and causes” relating to the attack on the Capitol by a mob of Trump supporters, including law enforcement agencies’ preparation and the “influencing factors that fomented” the attack aimed at stopping Congress’s certification of the 2020 election results.

Unlike the independent, 20-member commission that would allow each party to appoint an equal number of commissioners, the select committee will instead comprise eight members appointed by Pelosi, and three chosen by Kevin McCarthy, the House Minority Leader.

Republicans, for their part, opposed what they believed to be overtly partisan select committee, contending that the investigation the panel will undertake is so narrowly focused on Trump’s role in what happened on 6 January that it turns a blind eye to other instances of political violence, such as the 2017 shooting at a GOP lawmakers’ baseball practice.

“This has been created as a partisan issue at a time when it should not be partisan. And if you’re not partisan, then you include all the things that threaten us, that threaten this body, that threaten this building, and that threaten the people that work in it. Let’s be serious. If you’re serious, be inclusive, be complete and do the right thing,” said GOP Representative Brad Wenstrup of Ohio, who was among just a few Republicans who participated in House floor debate.