Republican lawmaker Mike Nearman is facing two misdemeanor charges after “knowingly” letting demonstrators into the locked building on 21 December last year.
The New York Times reported that lawmakers voted unanimously on Thursday to expel him from office, with Mr Nearman being the only person out of 60 to vote against the motion.
A recently resurfaced video showed Mr Nearman apparently coaching demonstrators and appearing to covertly tell people to text him so he could let them into the building.
“That is just random numbers that I spewed out. That’s not anybody’s actual cellphone,” Mr. Nearman said in the apparently streamed video.
He was then seen on security footage days later apparently following through on the so-called “Operation Hall Pass”, opening a door to the protesters which had been closed to the public due to the coronavirus pandemic.
After the videos illustrating the 23rd district’s Representative’s alleged role were revealed, members in the state’s Senate on both sides of the political spectrum called for his resignation.
House Speaker Tina Kotek, a Democrat, introduced a resolution to the House this week to expel the lawmaker if a two-thirds vote was met.
Republican lawmakers also wrote a letter to Nearman on Monday, “strongly recommending” that he step down.
All 22 House Republicans said in the joint letter that it was “in the best interest of your caucus, your family, yourself, and the state of Oregon for you to step down from your office.”
Following Thursday’s vote, Speaker Tina Kotek, a Democrat, described Mr Nearman’s alleged actions as “blatant and deliberate” saying he had shown no remorse for jeopardizing the safety of every person in the Capitol that day.”
After the incident, the lawmaker was charged with misdemeanor counts of first-degree official misconduct and second-degree criminal trespassing. He said he will seek trial by jury.
In an interview on the Lars Larson Show, a conservative talk radio program, he indicated that his actions were civil disobedience because he objected to the Capitol being closed to the public.
The protesters breached the Capitol as lawmakers met in emergency session to deal with the economic fallout from the pandemic, were pushed back out of the building by riot police.
At least five of the demonstrators were arrested. Some of the demonstrators had guns and carried banners in support of former President Donald Trump.
The Independent has contacted Mr Nearman for comment.
Additional reporting by the Associated Press