The controversial comedian Frankie Boyle has called for Top Gear host Jeremy Clarkson to be sacked "because he's a cultural tumour", in his latest outspoken attack on a public figure.

Boyle said that following Clarkson's apology and his final warning from the BBC after an online video emerged of him apparently mumbling the N-word in the nursery rhyme Eeny, Meeny, Miny Moe, in an outtake from the BBC2 programme, he "should be removed".

Boyle said: "[Clarkson] comes from a very bad place and the reason he's tolerated is that he's recognised by people in power … in fact he's a friend of [David] Cameron's." Increasing his vitriol towards the presenter, Boyle added: "He's in there like a fucking growth and he should be removed because he's horrible. Sack him because he's a cultural tumour."

Speaking at the Guardian Edinburgh international television festival, Boyle also described Rupert Murdoch as "obviously a c*** and fucking tumour" – which some might say is hypocritical given Boyle earned a substantial sum writing a column for Murdoch's Sun. Boyle defended himself, saying the newspaper was "easier to get jokes into than the BBC" and he could talk about things like war and austerity. The Scot recounted an anecdote about being in the same hotel as Murdoch and staff telling him that the media mogul went through newspapers with a marker pen.

Boyle also hit out at Mock the Week, a programme on which he used to appear, saying it would not let him talk about war, instead preferring jokes about sport.

He defended quotas for women on panel shows, asking: "How hard is it to get female panellists?" and said that as a guest host he had tried to get more women on Never Mind the Buzzcocks. He suggested inviting the comedian Sarah Millican on to the panel but, he said, "they implied I'd get sacked".

Boyle is not on TV as often as he used to be, with Channel 4's head of comedy, Phil Clarke, saying recently there was no place for him. The Scottish comedian's forthcoming projects are an episode of Live at the Apollo and a pilot on BBC iPlayer about the Scottish referendum – which he said was mostly because commissioners want to "avoid controversy".

Boyle said that in television there is a "layer of people whose job it is to reject things … and the trouble is, those people are at the top".

Asked if he would have to "act any differently or produce yourself differently" to get back on a long-running show, he implied he would have to tone down. "You would have to, because there's no space for that any more and also I'm not 35 any more, so I don't feel like doing loads of jokes about rape."

When asked if he could be "the old Frankie Boyle" and be on television now, he said no. However, he had no regrets about two of his most controversial jokes – one about the Olympic gold medal-winning swimmer Rebecca Adlington and the other about Katie Price's son, Harvey. They had been in context and, of the latter, he said: "It got signed off by everybody."

Boyle was mostly well-received by the audience at Edinburgh, drawing laughs for jokes about ITV's entertainment lineup ("like something from a cruise ship") and when he described Channel 4's schedule as "like Take a Break or Chat magazine".

On Scottish independence, Boyle said he was "all for it", but "it won't happen".