Donald Trump has challenged leading editors and politicians to debate him in public over his lie that Joe Biden beat him in 2020 through electoral fraud.

In a typically rambling statement on Sunday, the former president complained about “the heads of the various papers [and] far left politicians” and said: “If anyone would like a public debate on the facts, not the fiction, please let me know. It will be a ratings bonanza for television!”

Despite Trump’s insistence that “the 2020 election was rigged and stolen” – and his well-known fixation on TV ratings – it was not.

Even William Barr, an attorney general widely seen as willing to run interference for Trump, publicly stated there was no evidence of widespread electoral fraud.

Biden beat Trump by more than 7m in the popular vote and by 306-232 in the electoral college, a result Trump called a landslide when he beat Hillary Clinton by it in 2016. Clinton also beat him in the popular vote.

Trump’s proposal of a public debate – which seemed unlikely to bear fruit – extended to what he called “members of the highly partisan unselect committee of Democrats who refuse to delve into what caused the 6 January protest”.

The attack on the US Capitol, Trump said, was caused by “the fake election results”.

In a way, he was right. It was his lies about the election which led to the deaths of five people around the attack on Congress by a mob seeking to stop certification of Biden’s win, some chanting that Trump’s vice-president, Mike Pence, should be hanged.

At a rally near the White House shortly before the riot, Trump told supporters to “fight like hell” in his cause. He was impeached for inciting an insurrection but acquitted when only seven GOP senators found him guilty, not enough to convict.

On Sunday, Adam Schiff, the Democratic chair of the House intelligence committee and a member of the 6 January panel, told CNN: “We tried to hold the former president accountable through impeachment. That’s the remedy that we have in Congress. We are now trying to expose the full facts of the former president’s misconduct as well as those around him.”

To adapt the Tennessee Republican Howard Baker’s famous question about Richard Nixon and Watergate, the House committee is focusing on what Trump knew about plans for protest and possible violence on 6 January – and when he knew it.

Numerous Trump aides and allies have been served with subpoenas. Most, like the former White House strategist Steve Bannon, who has pleaded not guilty to contempt of Congress in the first such case since 1983, have refused to cooperate.

Schiff said a decision on a possible contempt charge for Mark Meadows, Trump’s last White House chief of staff, would likely be made in the coming week.

It seems unlikely any senior figure in the US media or among Democrats in Congress or state governments will take up Trump’s challenge to debate him in public.

Observers including the former New Jersey governor Chris Christie, who helped Trump prepare for his debates against Biden, agree that a near-berserk performance in the first such contest did significant damage to Trump’s chances of re-election.

At one point on a chaotic evening in Cleveland in September, Biden was so exasperated as to plead: “Would you shut up, man? This is so unpresidential.”