ANIMOSITY among MSNBC anchors has reached a mile-high peak at the Democratic National Convention in Denver, with on-air squabbling between such big egos as Joe Scarborough, Keith Olbermann, Chris Matthews and David Shuster.

Scarborough, who served in Congress as a Republican representative from Florida, seems to be particularly touchy being the only host who isn't openly pro-Democratic.

Yesterday, after Shuster referred to "your party, the Republican Party," Scarborough went off, sparking a seven-minute exchange.

"I will let you know that 'my party,' my party loathes me much more than your party, the Democratic Party, loathes me," Scarborough seethed. "What about your party? What's your party, David Shuster? David, what's your party?"

"I have no party. I'm a complete independent," Shuster replied.

"Oh, I feel so comforted by the fact that you're independent. I bet everyone at MSNBC has 'independent' on their voting cards," said Scarborough.

Scarborough declined to talk to Page Six, but sources say he and NBC anchor Tom Brokaw disagree with MSNBC's decision to position itself as the channel for George W. Bush-haters.

At a forum on Sunday, when Pennsylvania Gov. Ed Rendell called MSNBC "the official network of the Obama campaign," Brokaw said, "I think Keith has gone too far. I think Chris has gone too far."