Ludacris was praised by Barack Obama earlier this year
A song by rap star Ludacris criticising Barack Obama's opponents has been called "outrageously offensive" by the US presidential candidate's campaign.
Politics As Usual calls President Bush "mentally handicapped", and insults both Hillary Clinton and John McCain.
"Ludacris is a talented individual but he should be ashamed of these lyrics," said Mr Obama's spokesman Bill Burton.
The rap star's publicist initially declined to comment, reported the Associated Press.
The musician used a misogynistic term to describe Mrs Clinton and urged Mr Obama against appointing her as his running mate, saying that she "hated on you".
Mr McCain, the Republican candidate for the presidency, does not belong in "any chair unless he's paralysed", according to the rapper.
Mr Burton added: "As Barack Obama has said many, many times in the past, rap lyrics today too often perpetuate misogyny, materialism, and degrading images that he doesn't want his daughters or any children exposed to."
The Ludacris song urges black people to cast their votes in the forthcoming election, and lends his support to Mr Obama's bid.
The lyric "the world is ready for change 'cause Obama is here" is repeated throughout the track.
In an interview with Rolling Stone magazine earlier this year, Mr Obama included Ludacris when describing hip-hop stars he considered "great talents and great businessmen".
In 2006, before he announced his intention to run for president, the politician met the rapper privately in Chicago to discuss youth issues.