Brit family feud with dad Jamie and K-Fed gets nasty!
Britney has threatened to abandon her $100 million concert tour – throwing her comeback into chaos infuriating both father and ex-hubby.

The pop star is set to embark on a grueling 33-city Circus concert tour March 3.

"But Britney doesn’t want to do it, and she’s telling her father Jamie that," an insider told The ENQUIRER. "All the dates are booked – and $100 million would be lost if she bails.

"Both her father and ex-husband Kevin Federline are telling her she has to go on for the sake of her kids and their financial future. So Britney is really feeling the pressure, and she says she can’t handle the tour’s whirlwind schedule.

"She is already exhausted getting in shape for the trip. And her focus has changed, too – Britney just wants to be a stay-at-home mom to her two boys. Britney feels like she is being forced to tour. Jamie has made it clear he wants to get her back to where she was."

Especially for the bucks –  for both papa and ex-hubby.

But Britney hates the tour’s set-up, which includes Kevin – who has custody of their boys – tagging along. That concession was the only way she could have the boys with her, so she reluctantly agreed, says the source.

"Britney can’t back out now – there’s just too much at stake. But her friends are asking if she can juggle all this pressure and keep from having another meltdown."