From CNN Political Editor Mark Preston

ATLANTA (CNN) -- Rep. John Murtha, D-Pennsylvania, said Sunday that his involvement in ABSCAM, and claims by critics that he helps his lobbyist brother will not harm his bid for a Democratic leadership post.

"Twenty-five years ago, they offered me money and I said I didn't want the money," he said about ABSCAM on ABC's "This Week." "I wanted the best for my district. It had 24 percent unemployment."

ABSCAM was an FBI sting operation in the early 80's that caught several lawmakers accepting bribes from a fictitious sheik in return for favors. Murtha was investigated and caught on camera talking to the undercover FBI agents, but never indicted in the sting.

Murtha also flatly denied charges by critics who say that he helps secure federal government contracts for his brother's clients.

"My brother was treated like everybody else," Murtha said on ABC. "We do it by the book. Everything we do in our office is by the book. And I think you'll see it's going to turn out a little differently than my detractors are pointing to."

Murtha is likely to face off against House Minority Whip Steny Hoyer, D-Maryland, for the majority leader position if Democrats win back the House in November.