Jeremy Corbyn has accused the BBC of being "obsessed" with trying to damage his leadership of the Labour Party.
In a behind the scenes documentary by Vice News, Corbyn's director of communications also reveals he believes there is a Conservative mole in the leadership office.
In the wake of last month's local elections, the Labour leader told the programme the "whole narrative" of the BBC had been that his party would do badly.
"There is not one story on any election anywhere the UK that the BBC will not spin into a problem for me," he said."It's obsessive beyond belief."
He added: "They are obsessed with trying to damage the leadership of the Labour Party."
Corbyn also takes aim at the "baseless and narrow" views of political columnists.
"The one thing I have learnt over the past six-months or so is how shallow, facile and ill-informed many of the supposed well-informed major commentators are in our media," he said.
“They are obsessed with trying to damage the leadership of the Labour Party”
- Jeremy Corbyn's view of the BBC
Corbyn is filmed attacking Guardian columnist Jonathan Freedland for writing a column that argued Labour has a problem with anti-Semitism.
The Labour leader describes the piece as "utterly disgusting, subliminal nastiness" and Freedland as "not a good guy".
George Eaton, the political editor of the left-leaning New Statesman magazine, is also criticised by one Corbyn aide as "the worst judge of anything".
For the documentary, Vice News followed the Labour leader and his team for eight weeks.
Following one prime minister's questions, Corbyn's communications chief Seumas Milne reveals he believes someone in the top Labour team is leaking PMQs information to David Cameron.
"This time they did (know the questions) because it leaked. It leaked from that meeting," he said.
"It's very annoying because it only happens about a third of the time, but it obviously gives them a little bit of extra time. Whenever there is a leak it gives them that advantage - it gives them the advantage on TV as well."
In one scene, Corbyn is shown rehearsing a high profile Commons speech shortly after Iain Duncan Smith resigned from the cabinet with an attack on George Osborne.
"It’s not up to me to throw in other than a couple of lines about 'the government’s in a mess'," he tells his aides.
Corbyn's criticism of the BBC is not the first time Labour had attacked the broadcaster since his election as leader.
In January, Milne accused the BBC of the "orchestration of political controversy" after a Labour shadow minister resigned live on its Daily Politics programme.
It was an accusation the BBC strongly rejected. Today Tom Baldwin, Ed Miliband's former communications director, defended the copropration.