The House January 6 committee on Thursday played as promised video footage of the Republican operative and Trump ally Roger Stone discussing the need for violence after the 2020 election, before 6 January 2021, the day of the deadly Capitol attack.

“Let’s just hope we’re celebrating,” Stone said, in footage obtained from a Danish documentary film-maker.

“I really do suspect that [the election result] will still be up in the air. When that happens, the key thing to do is to claim victory. Possession is nine tenths of law. ‘No we won, fuck you. Sorry, you’re wrong, fuck you.’”

In another clip, Stone said: “I say fuck the voting, let’s get right to the violence.”

To laughter, an associate with Stone said: “Start smashing pumpkins, if you know what I mean.”

In her opening statement at a hearing officially designated as a business meeting, to set up votes on further investigations, the California Democrat Zoe Lofgren laid out the committee’s interest in Stone.

Stone, she said, “is a political operative with a reputation for dirty tricks. In November 2019 he was convicted of lying to Congress and other crimes and sentenced to more than three years in prison. He’s also a longtime adviser to President Trump, and was in communication with President Trump throughout 2020. Mr Trump pardoned Roger Stone on 23 December 2020.”

Stone, she said, “apparently knew of Mr Trump’s intentions” to reject the election result long before election day.

The congresswoman said: “Although we don’t yet have all the relevant records of Roger Stone’s communications, even Stone’s own social media posts acknowledge that he spoke with Donald Trump on 27 December as preparations for January 6 were under way.”

Stone, Lofgren showed, discussed the idea of appointing a special counsel to “ensure those who are attempting to steal the 2020 election through voter fraud are charged and convicted and to ensure Donald Trump continues as our president” – an idea the president is known to have discussed with allies and advisers.

Lofgren mentioned links between Stone and the Capitol attack, including his attendance at the Willard hotel the night before January 6, as Trump allies planned their actions the next day, and his links with the Oath Keepers and the Proud Boys, extremist rightwing groups who led the Capitol riot.

“Individuals from both of these organisations have been charged with a crime of seditious conspiracy,” Lofgren said. “… Multiple associates of Roger Stone from both the Oath Keepers and the Proud Boys have been charged with this crime.”

Lofgren also played footage of Stone refusing to answer questions from the committee, invoking his fifth-amendment right against self-incrimination.

The committee also played footage of Steve Bannon, Trump’s 2016 campaign chair who became a White House strategist, discussing what would happen on January 6, and revealed a hitherto unseen memo from Tom Fitton, another pro-Trump activist.

“The select committee got this pre-prepared statement from the National Archives,” Lofgren said, displaying and describing the draft statement sent by Fitton on 31 October, three days before election day.

According to Fitton’s proposed memo, Trump would simply “declare we had an election today and I won”.