(Note obscenity in paragraph 6)
* Scher says he told Edwards affair would destroy career
* Pair reportedly clashed over matter in heated phone call
* Heiress didn't condemn Edwards after revelations - witness
By Colleen Jenkins
GREENSBORO, N.C., May 4 (Reuters) - A political adviser was told to butt out when he warned former U.S. Senator John Edwards that pursuing an extramarital affair with a videographer would sink his presidential ambitions, he testified at Edwards' campaign finance trial on Friday.
Peter Scher, who first worked with Edwards when he was the Democrats' 2004 vice presidential nominee, said the politician denied having a sexual relationship with Rielle Hunter when Scher broached the subject in September 2006.
At the time, Edwards had not yet declared his candidacy for the 2008 Democratic presidential nomination.
"I told him if it was true that he was having an affair with Ms. Hunter, he should not run for president," Scher testified as the second week of Edwards' trial neared its end. "If it was true, eventually it would come out and it would destroy his political career."
Scher said he again confronted Edwards about the affair in a heated phone call after learning Hunter was still traveling with the former senator from North Carolina despite staff concerns. This time, Edwards responded that he didn't need a babysitter and told Scher to back off, the former adviser recalled.
"He told me to go fuck myself," said Scher, who stopped serving as an outside adviser to Edwards at that point.
Edwards, 58, is standing trial in Greensboro on six counts of election law violations. Federal prosecutors accuse him of directing an aide to solicit more than $900,000 in illegal campaign contributions in order to conceal his relationship with Hunter during his failed 2008 presidential bid.
The government says Edwards, at the time married with three children, knew revelations about his affair and Hunter's resulting pregnancy would ruin his image and doom his campaign.
The defense argues Edwards knew nothing about the secret payments, which his attorneys say were intended to hide Edwards' pregnant mistress from his cancer-stricken wife, Elizabeth, and not to influence the election.
The wealthy heiress who supplied the bulk of the money did not know at the time that it was being used to help provide for Hunter, according to a close friend's testimony on Friday.
But Bryan Huffman, an interior decorator, said 101-year-old Rachel "Bunny" Mellon wasn't particularly upset when she later learned some of the payments went toward Hunter's living expenses and medical care.
Huffman said Mellon badly wanted to see Edwards elected president and believed she was helping him with an expense unrelated to the campaign.
She wrote checks totaling $725,000 in Huffman's name, and he forwarded the money to Edwards' aide Andrew Young and his wife, who deposited the checks into their personal accounts.
The defense says Andrew Young, who has immunity, arranged the financial scheme and used much of the money for his own benefit.
Mellon didn't condemn Edwards for having an affair after the truth was revealed, Huffman said. However, "she thought that maybe you should pay for your girlfriend yourself," he said. (Editing by Paul Thomasch and Xavier Briand)