A crucial witness before the House January 6 committee testified that senior aides had described how Donald Trump thought his vice-president, Mike Pence, deserved to be hanged for not blocking certification of election results, as demanded by the mob that attacked the US Capitol.

Describing events at the White House on the afternoon of 6 January 2021, Cassidy Hutchinson, a former aide to Trump and his chief of staff, Mark Meadows, said: “I remember Pat [Cipollone, the White House counsel] saying something to the effect of, ‘Mark, we need to do something more. They’re literally calling for the vice-president to be fucking hung.’

“And Mark had responded something to the effect of, ‘You heard him, Pat, he thinks Mike deserves it. He doesn’t think they’re doing anything wrong.’

“To which Pat said something like, “This is fucking crazy. We need to be doing something more.”

Liz Cheney, the committee vice-chair, repeated: “When rioters chanted ‘hang Mike Pence’, the president of the United States, Donald Trump, said that, quote, ‘Mike deserves it’ and that those rioters were not doing anything wrong.”

Hutchinson’s description of Trump’s words was included in a previous hearing, via recorded testimony. The committee had also previously shown that at one point the mob was just 40ft away from Pence.

Hutchinson appeared in person on Tuesday, in a sixth public session announced at short notice and full of explosive revelations.

Cheney, from Wyoming and one of two anti-Trump Republicans on the January 6 committee, played a recording in which Trump, speaking to Jon Karl of ABC News, refused to condemn the rioters who chanted for Pence to be hanged.

“Because it’s common sense,” Trump said. “It’s common sense that you’re supposed to protect … if you know a vote is fraudulent, how can you pass on a fraudulent vote to Congress?”

Electoral college results confirming Trump’s defeat by Joe Biden were not fraudulent. Trump’s claim that they were and his instruction to “fight like hell” in service of his lie fueled the mob that attacked the Capitol.

Cheney said: “President Trump’s view that the rioters were not doing anything wrong and that, quote, ‘Mike deserved it’, helps us to understand why the president did not ask the rioters to leave the Capitol for multiple hours.”

The mob did not succeed in stopping certification of election results. A bipartisan Senate committee linked seven deaths to the riot. More than 840 people, some members of far-right groups, have been charged with seditious conspiracy.