'RHOC' Already At Odds! Veteran Tamra Barney Can't Stand New Castmember Danielle Gregorio's 'Over-The-Top Need For Attention'

The new season of Real Housewives of Orange County hasn't even aired yet, but the drama is already brewing!

When you throw new cast members into the mix, the claws are bound to come out — and RadarOnline.com has exclusively learned that's exactly what is transpiring between veteran star Tamra Barney and newbie Danielle Gregorio.

"Danielle signed on for this show knowing full well that she'd have to bring drama and make waves with the ladies in order to stay relevant," an insider told RadarOnline.com.

"And it's not going over well with the women who have been on the show for years. Tamra is really annoyed by everything Danielle does at this point and just feels like she sees right through her."

But it was while the ladies were filming in Bali and Hong Kong that Gregorio really hit a nerve with Barney, sources say.

As RadarOnline.com previously reported, the new ladies “are fitting in perfectly because they love to fight as much as the other women.”

Gregorio is good friends with co-star Heather Dubrow, who campaigned for her pal to get on the show, which only brings more controversy to the OC because Barney and Dubrow are also great pals.

Gregorio is willing to go to any length to catapult herself into fame, sources previously told RadarOnline.com, so fighting with other cast members is just the tip of the iceberg.

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"Danielle wants to be famous and is willing to go to great lengths to accomplish that. She said she is going to create sh*t to make the drama for the show," the insider previously told RadarOnline.com.