Failed presidential candidate John Edwards considered leaving his cancer-stricken wife and went to extraordinary lengths to cover-up a reckless affair that led to him fathering a child with his mistress, according to a new book.

The forthcoming publication of The Politician by Andrew Young, Mr Edwards's long serving assistant, had already forced the Democratic Party's vice-presidential candidate in 2004 to admit paternity of a two-year-old girl born to Rielle Hunter, who had worked as a campaign videographer.

Excerpts made available yesterday portrayed the former North Carolina senator and early frontrunner in the 2008 primary campaign as obsessed with his hair, irredeemably deceptive and contemptuous of his supporters.

He allegedly once told Mr Young that he disliked appearing at state fairs where "fat rednecks try to shove food down my face. I know I'm the people's senator, but do I have to hang out with them?" The book also describes Mr Young's shock at finding a compromising videotape of Mr Edwards and a naked, pregnant Miss Hunter.

Neither she nor her husband has commented on the book. His political career in ruins, Mr Edwards spent part of last week in Haiti helping with relief efforts.