Former Republican vice presidential candidate Sarah Palin is striking back hard at her daughter’s ex-fiance, Levi Johnston, for what she called “mean-spirited, malicious and untrue attacks.”

Palin, and Johnston, who had a child out of wedlock with Palin’s daughter, Bristol, have been in a war of words since Levi and Bristol broke off plans to marry early this year.

Johnston appeared on CBS’ “Early Show” and repeated a charge he made in a recent Vanity Fair interview that Sarah Palin would often refer to her son with Down Syndrome, Trig Palin, as being “retarded.”

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Johnston also talked about his plans to appear nude in Playgirl magazine, saying it will be done tastefully.

“I’m not gonna just go out there and get naked,” he said.

All this comes as Palin prepares to issue her memoir next month, “Going Rogue, An American Life.” She resigned as Alaska governor last summer and remains popular with conservative voters after running as John McCain’s vice presidential candidate last year.

In a statement issued by her spokeswoman, Palin said she had tried to ignore the “mean spirited, malicious and untrue attacks on our family.”

“We, like many, are appalled at the inflammatory statements being made or implied. Trig is our ‘blessed little angel’ who knows it and is lovingly called that every day of his life. Even the thought that anyone would refer to Trig by any disparaging name is sickening and sad,” she said.

She also criticized CBS for giving Johnston publicity.

“CBS should be ashamed for continually providing a forum to propagate lies. Consider the source of the most recent attention-getting lies — those who would sell their body for money reflect a desperate need for attention and are likely to say and do anything for even more attention,” she said.

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Photo credit: Reuters/Matt Sullivan (Sarah Palin waves in front of daughter Bristol and son Trig in August 2008)