X FACTOR smackdown –KHLOE KARDASHIAN & MARIO LOPEZ despise each other with the fury of a thousand suns!

 T HE prospective new hosts of “The X Factor” – reality TV  Khloe Kardashian and “Extra” host Mario Lopez – are already at each other’s throats!

“The show hasn’t even started taping yet and the knives are out!” a network insider told The ENQUIRER.

“Mario thinks Khloe is an airhead, and she thinks he’s a musclebound stuffed shirt.

“They’re already vying for the spotlight, and the real competition is going to be which one will be the bigger pain in the butt for ‘X Factor’ brass when production starts.”

Each one is set to get a fat $1 million paycheck, but hammering out their deals has been a nightmare, said the source.

“They both demanded exactly the same amount of air time, a completely even distribution of promotional commitments, the same dressing room trailers and the same down-to-the-penny wardrobe, hair and makeup budgets,” said the source.

“Mario even tried to get approval of Khloe’s wardrobe because he’s terrified her cleavage is going to detract from his muscles!”

On the surface, Khloe is the most laid-back, no-nonsense of the Kardashian sisters, “but she’s hoping this gig could lead to a job on a show like ‘The View’ or even her own series,” the source said.

“Meanwhile, Mario is all about business. Plus, he always has to be the bigger star, so it infuriates him to have an equal role with someone as popular as Khloe.

“Mario and Khloe each feel they’ll be the new name draw for ‘X Factor’ fans – and for the producers, the headaches have just begun.”