The BBC has been accused of legitimising right-wing extremists by giving the former Breitbart London editor Raheem Kassam a "platform to spout bile" on Radio 4's flagship Today programme.
Mr Kassam, who formerly served as chief adviser to Nigel Farage when he was Ukip leader, was brought on to discuss the release of Tommy Robinson from prison.
A prominent supporter of the far-right figurehead, he has led “Free Tommy” rallies and publicised his cause during a two-month imprisonment for contempt of court.
But Mr Kassam’s views were not debated on the Today programme, which broadcast his comments in a pre-recorded interview.
Labour MP David Lammy said Radio 4 “did not even bother to push back on [Mr Kassam's] claims that Steve Bannon – the former Breitbart chairman and chief strategist to Republican president Donald Trump - was a “Kennedy Democrat”.
“The legitimation of white supremacists and fascists who plan to interfere in our politics is a grave threat,” Mr Lammy added.
Many listeners took to Twitter to ask why Radio 4 did not invite guests to counter Mr Kassam’s claims, and it was further criticised for allowing Jordan Peterson, a professor celebrated by the misogynist “incel” movement and Islamophobes, to appear later in the programme.
Meanwhile, BBC 5 Live Breakfast broadcast comments by Ezra Levant, Robinson's former employer at The Rebel Media, a Canadian far-right website.
The furore came as figures showed the Today programme has lost more than 800,000 listeners in the past year, pulling in an average of 6.82 million every week.
Human rights lawyer Adam Wagner said the broadcast allowed Mr Kassam “to make out he's a legal expert commenting on legal policy”, asking: “What on earth is going on?”
One critic said the BBC had given him “a platform to spout dishonest and divisive bile on national radio”, and another said he should “not be given the oxygen of publicity”.
Catherine Mayer, co-founder of the Women’s Equality Party, pointed out issues including climate change and gender equality had been “balanced” with deniers by the BBC, but it then “gives Raheem Kassam a solo slot to peddle far-right poison”.
A spokesperson for the BBC said: “Martha Kearney’s interview robustly challenged Raheem Kassam’s opinions and assertions on Tommy Robinson and Islam. She also clearly explained the legal points around his release on bail and impending re-trial.
“We believe our job is to give our audience facts, analysis and information, especially in the case of contentious issues which are surrounded by misinformation.”
Mr Kassam appeared to call for people to watch the Facebook Live video that saw Robinson jailed, after it violated blanket reporting restrictions and threatened to derail a trial at Leeds Crown Court.
He claimed his own network, including his former manager Mr Bannon, is not far-right as they set up a new pan-European political alliance called The Movement.
Mr Kassam said it would “unite what we think of as patriotic, populist nationalist parties across the continent”, including Ukip.
He said his Today programme interview was pre-recorded on Wednesday and claimed he would publish “the full audio if they cut things out”.
As criticism raged on Twitter, Mr Kassam said he felt the interview was “tough but fair”.
Mr Kassam has previously hit out at journalists online, publishing a photo of an LBC Radio producer alongside his contact details and urging Twitter and Facebook followers to “tell him what you think" last month.
After the Court of Appeal’s verdict on Robinson, he accused “the media” of lying over his case and told journalists: “F*** you…we won.”
Judges upheld a finding that the English Defence League co-founder committed contempt of court during a trial in Canterbury, but quashed a second finding in Leeds from May and ordered his release from prison.
The appeal was allowed because of “fundamentally flawed” legal procedures at Leeds Crown Court and judges released Robinson on bail to attend another hearing over the allegations.
The 35-year-old is accused of breaking blanket reporting restrictions on an ongoing set of trials, and causing an application for a jury to be dismissed, with a Facebook Live video on 25 May.
The Court of Appeal’s judgment said Robinson’s interest in the case was “sparked by the ethnicity or religion of the defendants” and that he made “generally prejudicial remarks…capable of amounting to a freestanding contempt of court”.
Robinson’s lawyer argued that the case should not be re-heard but judges refused, saying the contempt allegations must be settled in the public interest.
“The alleged contempt was serious and the sentence might be longer than that already served if a finding is again made” against Robinson, judges warned.
Robinson, whose real name is Stephen Yaxley-Lennon, has previous convictions for offences including assault, threatening behaviour, mortgage fraud and false representation.
After leaving the EDL and failing to set up a British arm of the German anti-Islam Pegida movement, he now characterises himself as an “independent reporter” and has spent the last two years touring the world and building connections with far-right figures in the US and Europe.
Robinson has emerged from prison with more money and more international support than when he was jailed in May, receiving almost £20,000 of bitcoin donations while in prison.
Robinson's following on social media has also surged and he has garnered public support from prominent figures including the US president's son, Donald Trump Jr.
“I’d have done six months just for that recognition,” he purportedly wrote in a letter from prison.