(CNN) -- Sen. Barack Obama's reference to "lipstick on a pig" has Republicans demanding an apology and Democrats accusing Sen. John McCain of a "pathetic attempt" to play the gender card. Barack Obama used the "lipstick" line at a campaign event in Lebanon, Virginia, on Tuesday. McCain's campaign said Obama's remarks were offensive and a slap at Republican vice presidential nominee Sarah Palin -- despite the fact that the Arizona senator himself used the phrase last year to describe a policy proposal of Hillary Clinton's. Obama shot back Wednesday and accused the McCain campaign of engaging in "lies" and "swift boat politics."
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NEW: Barack Obama slams Republicans for "lies" and "swift boat politics"
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Obama said Tuesday "You can put lipstick on a pig, but it's still a pig"
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McCain camp says line was an attack on Palin; Obama camp says it was not
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Many politicians have used the line; former McCain adviser used it in her book title
Obama made his controversial "lipstick" remarks at a @placeholder campaign stop late Tuesday afternoon.