Talk Show Showdown! Ellen DeGeneres & Kelly Clarkson Fighting Over Guests

The dirty little secret about daytime talk shows is how ugly it gets behind-the-scenes booking the biggest guests first, a source revealed exclusively to STRAIGHT SHUTER.

And with the huge success of the Kelly Clarkson show, everyone, including Ellen Degeneres is feeling a little threatened!

“The rule is very clear, and every celebrity, manager and agent knows it, if you want to be on Ellen’s show, she must go first, she will not follow any other daytime show including Kelly," snitched the insider.

"So if the cast of The Voice want to sit down with Kelly, that’s fine, but Ellen will pass and get you next time you have something to promote,” sources tell STRAIGHT SHUTER. “At the moment, Ellen is being very supportive of Kelly, but do not think Clarkson’s successful debut has gone unnoticed.”

As RadarOnline.com readers know, while there's no denying Clarkson has had a great amount of success with her new show The Kelly Clarkson Show, the gig hasn't come without its drama.

RadarOnline.com previously reported exclusively Carrie Underwood turned down an invite to Clarkson's show, fanning the flames of the feud that’s been simmering between the American Idol champions.

“There were no explanations or niceties — and Underwood’s people just turned Clarkson down flat!” spilled an insider. “Kelly was furious!”

Both Clarkson, 37, and Underwood, 36, have been supportive of each other in public. But sources told RadarOnline.com the superstars are locked in a fierce behind-the-scenes rivalry!

Now, with a young fresh face in the talk show scene, sources reveal spitfire DeGeneres, 61, who started The Ellen DeGeneres Show in September 2003, is feeling intimidated.