Rep. Liz Cheney, R-Wyo., vice chair of the committee, told reporters to prepare for a substantial hearing despite Trump's former campaign manager Bill Stepien having to drop out from testifying live at the last minute due to a family emergency.

"We're going to have a very important and effective set of hearings. As you know, Mr. Stepien has appeared previously, and so we'll be able to provide the American people with a lot of interesting new and important information that Mr. Stephens provided to us previously," Cheney said.

She also confirmed the committee will show video of Stepien's interview.

In previewing Monday's hearing, which will be guided in part by Rep. Zoe Lofgren, D-Calif., House select committee aides said members would focus on how Trump and his campaign pushed the 'big lie' to millions of supporters after the election, despite knowing he lost.

The questioning of live witnesses, along with clips of interviews the committee videotaped with other key witnesses, will show how Trump was told he had lost the election and lacked evidence of widespread voter fraud but continued to claim the election was stolen from him, aides told reporters on Sunday night.

The committee hearing will show "how litigation to challenge elections usually works," and argue that Trump had an "obligation" to "abide by the rule of law" when his dozens of lawsuits failed in courts across the country, they said.

Trump's former campaign manager Bill Stepien will no longer testify live on Monday, citing a family emergency, but the committee will still hear from several live witnesses.

Chris Stirewalt, the former Fox News political editor who was fired after defending the network's early projection that Trump had lost Arizona on election night, is scheduled to testify this morning.

A second panel of witnesses includes Al Schmidt, a former Republican city commissioner in Philadelphia who repeatedly debunked claims of fraud in the state; veteran GOP election lawyer Ben Ginsberg, and Byung "BJay" Pak, a former U.S. Attorney for the Northern District of Georgia.

Pak previously told Senate investigators he resigned in January 2021 after learning Trump sought to fire him over not doing more to amplify his false claims of widespread election fraud in Georgia.

The House select committee has delayed its 10 a.m. start time Monday, citing a family emergency for witness Bill Stepien, former President Donald Trump's 2020 campaign manager, who will no longer testify.

"Due to a family emergency, Mr. William Stepien is unable to testify before the Select Committee this morning. His counsel will appear and make a statement on the record," the committee said in a statement. "The hearing will convene approximately 30 to 45 minutes after the previously announced 10:00am start time."

Stepien had been subpoenaed to testify on Monday.

The committee said his counsel will appear and make a statement on the record.