Days before the 2020 presidential election, Donald Trump was already planning to declare victory on election night, even if there was no evidence he was winning, according to a leaked Steve Bannon conversation recorded before the vote.

In the audio, recorded three days before the election and published by Mother Jones on Wednesday, Bannon told a group of associates Trump already had a scheme in place for the 3 November vote.

“What Trump’s gonna do is just declare victory. Right? He’s gonna declare victory. But that doesn’t mean he’s a winner,” Bannon, laughing, told the group, according to the audio.

“He’s just gonna say he’s a winner.”

The release of the audio comes as Bannon is due to go on trial Monday for criminal contempt, after he ignored a subpoena last year from the House select committee investigating the attack on the US Capitol in 2021.

On Wednesday Bannon’s attorneys again asked a federal judge to delay the trial, citing references to some of his past comments during Tuesday’s public hearing of the select committee, and the planned airing of a CNN documentary on Bannon the day before his trial is due to start.

Both events create “the very serious risk of prejudice here” among jurors, Bannon’s lawyers said, according to CNBC.

On Monday a federal judge dismissed a previous motion by Bannon to delay the trial, and ruled Bannon could not make two of his principal defences to a jury.

That came after Bannon said he was now willing to testify before the House select committee, an offer dismissed by the justice department as a “last-ditch attempt to avoid accountability”, and US district judge Carl Nichols said the trial must go ahead.

Before the 2020 election it had been reported that Trump planned to declare victory early, and in the Mother Jones audio Bannon says the former president planned to “take advantage” of the likelihood that Democratic postal votes would be tallied later than in-person Republican ballots.

Trump did exactly that hours after the election, claiming: “Frankly, we did win this election”, even as millions of ballots were yet to be counted, and after Fox News had – correctly – called the state of Arizona for Joe Biden.

“As it sits here today,” Bannon said later in the audio, describing a scenario in which Trump held an early lead in swing states, “at 10 or 11 o’clock Trump’s gonna walk in the Oval, tweet out, ‘I’m the winner. Game over. Suck on that.’”

Mother Jones said the audio, which is nearly an hour long, was recorded during a meeting between Bannon and supporters of Guo Wengui, an exiled Chinese mogul whom Bannon helped launch a series of rightwing websites.

In the meeting Bannon said Democratic supporters were more likely than Republicans to vote by mail, meaning their votes would be counted and reported later.

That would lead to a public perception that Trump was winning the election, according to the audio. Democrats would “have a natural disadvantage”, Bannon said.

“And Trump’s going to take advantage of it. That’s our strategy. He’s gonna declare himself a winner.”

“So when you wake up Wednesday morning, it’s going to be a firestorm,” Bannon said.

“You’re going to have antifa, crazy. The media, crazy. The courts are crazy. And Trump’s gonna be sitting there mocking, tweeting shit out: ‘You lose. I’m the winner. I’m the king.’”

Axios reported before the 2020 election that Trump had “told confidants he’ll declare victory on Tuesday night if it looks like he’s ‘ahead’”, and Bannon said on his podcast on the day of the election that Trump would claim victory “right before the 11 o’clock news”. The Mother Jones audio supports both claims.

Trump, the only US president to have been impeached twice, lost the election: Biden won 306 electoral votes to Trump’s 232. About 81.3 million people voted for Biden, compared with 74.2 million for Trump.