Election deniers are not “going to go away organically”, and if they are ever to vanish, US voters must signal “that truth matters” beginning with the upcoming midterms, according to a Republican member of the congressional committee investigating the January 6 attack on the Capitol.

Adam Kinzinger’s latest remarks on the baseless insistence by Donald Trump’s allies that fraudsters denied him a second term in the Oval Office and handed the 2020 election to Joe Biden came Sunday, days after the House January 6 select committee unanimously moved to subpoena the former president’s testimony over his knowledge of the deadly Capitol attack.

Kinzinger, one of two Republicans on the nine-member January 6 panel, has long called the Capitol attack the inevitable culmination of Trump’s lies – buoyed up by supporters in and out of elected office – that he was robbed of victory over his Democratic rival Biden. On Sunday he made arguably one of his most impassioned pleas yet for voters to realize the only way to minimize chances of a Capitol attack repeat, or even an escalation, was to punish candidates denying the legitimacy of the 2020 presidential race at the ballot box.

“I don’t think this is just going to go away organically – this is going to take the American people really standing up and making the decision that truth matters,” Kinzinger said on ABC’s This Week when host George Stephanopoulos mentioned the large number of midterm candidates in state and federal races amplifying Trump’s electoral lies.

“I don’t care if you’re a Republican or Democrat because the battle right now is truth and the battle is the preservation of democracy.”

Kinzinger, in his conversation with Stephanopoulos on Sunday, reiterated that the subpoena which the House Capitol attack panel was working on issuing to Trump wouldn’t be a request. Trump’s rambling, 14-page reply to the subpoena, titled “the presidential election of 2020 was rigged and stolen”, never said whether he intends to comply – he once was eager to speak on his own behalf before the panel, but he since has appeared to grasp the potential pitfalls of making statements to investigators.

Nonetheless, “he’s required by law to come in” and either testify or invoke his rights against self-incrimination, Kinzinger said. “And he can ramble and push back all he wants – that’s the requirement for a congressional subpoena to come in.”

The Illinois congressman said he anticipated a negotiation between the committee and Trump’s camp about whether the former president’s testimony in front of the panel would be live. The panel has rarely accepted testimony with conditions from any witnesses, with the notable exception of former Trump White House aide Cassidy Hutchinson.

Kinzinger also wouldn’t say whether he believed federal prosecutors would charge Trump with criminal contempt of Congress if he defies the subpoena.

“Look, that’s a – that’s a bridge we cross if we have to get there,” Kinzinger said.

Trump’s former strategist Steve Bannon was found guilty of criminal contempt of Congress in July after he refused to provide testimony and documents subpoenaed by the House January 6 committee. But Trump could avail himself of immunity which Bannon could not.

At least nine deaths, including the suicides of officers traumatized by having to respond to the scene, have been linked to the Capitol attack staged by Trump supporters on the day Congress was supposed to certify his defeat at the hands of Biden.

Members of the congressional committee investigating the attack have said the subpoena to Trump is necessary because his singular role at the center of events leading up to January 6 required a full accounting.

They reportedly believe Trump’s testimony could resolve a number of pending issues, including his contacts with political operatives at the Trump war room at an upscale hotel near the Capitol on the day before the building was attacked.

The work of Kinzinger and fellow Republican Liz Cheney on the House January 6 committee has been costly for both. Cheney lost a bid for another term to Trump-backed primary challenger Harriet Hageman.

Kinzinger, whose office has reportedly been inundated with death threats, chose to not run for re-election and has started a political action committee, Country First, which in part aims to recruit candidates from both parties for local election clerk offices who wouldn’t subvert the results of races.

“I would love to say this was going to happen easily,” Kinzinger said. “It’s going to take everybody’s work out there working hard because I don’t think you want to leave your kids a country … like what we’ve been living in.”