Published on: May 6, 2009

John Edwards' furious mistress is demanding he submit to a DNA test, The ENQUIRER has learned exclusively!

Rielle Hunter - the longtime secret lover of the disgraced 2-time presidential candidate - wants definitive proof that Edwards is the father of her 14-month-old love child Frances and is working with a lawyer to take legal action, say sources.

The blonde divorcee - who gave birth in February 2008 - was slammed in the explosive new book Resilience written by the ex-senator's cancer-stricken wife Elizabeth.

The ENQUIRER was the first to expose the extramarital affair in 2007, and Rielle's sudden move to determine paternity is a clear signal that she is no longer willing to protect the philandering politician, who still has not admitted that he's the father of her baby.  Edwards recently confirmed he's also the subject of a federal probe into possible campaign funds misuse in paying off hush money to Hunter.

"Rielle - probably naively - now realizes she had held onto a false promise that if she continued to take part in the cover-up John had engineered, they'd be together in the future," a close source told The ENQUIRER.

"She was willing to protect John for the sake of the child. She agreed to allow a crony of his to claim he was the baby's father, and she even kept the name of the father blank on the birth certificate.

"But now she can see there's never going to be a future with John - and she feels he's lied about his promise to keep Elizabeth from trashing her in the book," the insider divulged.

"Rielle is so infuriated by his and Elizabeth's actions that she's throwing her loyalty to him out of the window!"

The source added: "Rielle wants the paternity of her daughter Frances finally established. It could ruin John for good because even after admitting the affair, he vehemently denied being the father!"

For the full story with all the details you won't find anywhere else - pick up the ENQUIRER - on sale now!