"Comedian Frankie Boyle has said The Daily Mirror newspaper has "misunderstood" the context of his use of language in jokes.
He was giving evidence at the High Court in London where he is suing the Mirror Group for an article that described him as "racist".
Boyle said the accusation of racism "goes against everything I've tried to do in my work, to do in my life".
The Mirror is defending the article published on 19 July 2011.
Giving evidence on the second day of the trial, Mr Boyle said: "If I take this on the chin it sets a very serious precedent. I think the idea of taking racism down to this casual level is a very serious thing."
Lawyers for the Mirror Group described Boyle as a "racist comedian" who gratuitously exploits negative stereotypes of black people for "cheap laughs".
The newspaper has defended itself "on the basis of truth and fair comment".
Complaints
Jurors were also shown footage from the BBC satirical show Mock The Week, in which Boyle and other comedians discussed immigration.
The Glasgow-born comedian said he was "pretending" to be someone with racist views during the episode.
He added that he has "actively campaigned" against racism and he thought it was "important" to highlight the issue in his routines by mocking the attitudes of racists, whom he "despised".
Boyle also blamed the British government, saying racism is "at the heart" of policy and the racist views of some people in power "trickle" through society.
"I don't think British people are racist. I think it is a top down thing. I think you have a lot of rich and conservative people who control our country who are racist and their views trickle down through things like tabloid papers.
"I think there is racism at the heart of British policy and has been both in Labour and Conservative times," he added.
The comedian's humour has often proved controversial with audiences.
Last year, broadcasting watchdog Ofcom upheld more than 500 complaints about his Channel 4 show Tramadol nights, during which he joked about model Katie Price's disabled son, Harvey.
In 2008, the BBC apologised when Boyle made a joke about Palestine on the Radio 4 comedy show Political Animal.
A year after that, BBC Two's Mock The Week was criticised by the BBC Trust over comments Boyle made on the show about swimmer Rebecca Adlington's appearance.
The trial is expected to last one week."
http://www.bbc.co.uk/news/entertainment-arts-19959227