The vice-chairwoman of the congressional committee investigating the January 6 attack on the US Capitol is not ruling out a criminal referral against Donald Trump, saying “a man as dangerous as [him] can never be anywhere near the Oval Office ever again”.

Liz Cheney’s remarks Sunday came after the committee’s chairman, Bennie Thompson, once said he did not expect the panel to indicate whether or not it would make a recommendation for federal prosecutors to charge the former president with an alleged role in the Capitol attack.

But, on a pre-recorded interview on ABC’s This Week, Cheney said she, Thompson and others on the committee could change their minds about their initial position after there was sworn testimony that Trump knowingly sent armed supporters to the Capitol on the day of the deadly attack in hopes of preventing the congressional certification of his defeat to Joe Biden in the 2020 election.

“What kind of man knows a mob is armed and sends the mob to attack the Capitol?” Cheney said on the program, adding that some in the crowd intended to hang Mike Pence that day. “His own vice-president [was] under threat … Congress [was] under threat. It’s just very chilling.”

The Republican representative from Wyoming correctly pointed out that the US justice department does not need a recommendation from the Capitol attack committee to charge Trump. But the panel of seven Democrats and two Republicans has made such referrals in the cases of former Trump aides Steve Bannon, Peter Navarro, Mark Meadows and Dan Scavino, who refused to cooperate with the committee.

The justice department – which is the only entity that can prosecute Trump – filed charges against Bannon and Navarro, who have pleaded not guilty. But it did not charge Scavino or Meadows.

Cheney, the daughter of former vice-president Dick Cheney, also spent much of her appearance Sunday defending the testimony of former Trump White House aide Cassidy Hutchinson at a recent committee hearing.

Many believe one part of Hutchinson’s testimony drew Trump closer than ever to demonstrable criminal conduct. She said Trumpknew some in the crowd for his speech near the White House on the day of the Capitol attack had handguns and rifles. Yet the then president still urged his audience to “fight like hell” and march on the Capitol, Hutchinson testified.

A bipartisan Senate committee later linked seven deaths to the ensuing violence at the Capitol. The key legal questions about Trump’s potential criminal exposure appear to be whether he intended to cause that violence and knew it was likely to occur, according to experts.

Hutchinson also testified under oath that Trump was furious that the Secret Service denied him permission to go to the Capitol that day, at one point even lunging for the steering wheel of the vehicle in which he was being driven that day. That aspect of her testimony was quickly met with reports in some quarters that senior Secret Service agents were prepared to testify that Trump never did that.

But on Sunday, Cheney said the committee was prepared to stage more sworn testimony about Trump’s “intense anger” at not being allowed to go to the Capitol at the height of the attack, the culmination of his false claims that electoral fraudsters had stolen the election from him.

“The committee is not going to stand by and watch [Hutchinson’s] character be assassinated,” Cheney said, in what was her first sit-down media interview during the panel’s six hearings so far.

The other Republican on the committee, Illinois congressman Adam Kinzinger, said in a separate interview on CNN’s State of the Union that he invited anyone who could contradict Hutchinson to “come and also testify under oath” like she did.

“We find her credible,” Kinzinger said.

Cheney said the hearings to this point had convinced her “Donald Trump can never be anywhere near the Oval Office again”. And she said she believed the Republican party would lose its legitimacy if it nominated Trump to run for president against Biden in 2024.

“He can’t be the party nominee,” Cheney said. “I don’t think the party would survive that.”

Cheney’s service on the January 6 committee has been costly for her politically. She is trailing in polls as she tries to fend off a challenge in a 16 August primary against one-time Trump critic turned loyalist Harriet Hageman.