THE KARDASHIAN Empire is in free-fall and heading for a rough landing!

With Kris Jenner’s much-hyped FOX talk show savaged by critics, Kourtney facing a paternity challenge from a man who claims to be her son Mason’s real dad, Khloe and Lamar Odom’s marriage crumbling amid ongoing cheat­ing allegations, and Kim falling under the control of domineering boyfriend Kanye West, a source says the family’s $180 million fortune – as well as the Kardashian brand – is collapsing.

To top it off, President Obama recently blasted Kim and Kanye for their opulent lifestyle in an interview.

“The glory days are over for the Kardashians,” said an insider. “They’re overwhelmed with bad publicity, diminishing ratings, personal heartbreaks and even fan and viewer fatigue.”

Kim – the family’s BIGGEST moneymaker – has been holed up since the June 15 birth of her daughter, North, apparently trying to figure out a way to distance herself from what she sees as a sinking ship.

“Kanye has been pushing Kim to defect for a while,” revealed the insider. “Now it’s finally going to happen.”

Kim, 32, hasn’t made a public appearance since becoming a new mom except for a recorded video message, shot from her bust up and played on an episode of her mom’s new talk show, “Kris.” She also appeared in a three-second Internet video.

“Kanye is calling the shots now,” ex­plained the insider. “He doesn’t want his baby mama seen until she’s back in tip-top shape, and that’s been a slow-going process.”

As The ENQUIR­ER reported, Kim and Kanye’s infant could have been a $250 million bonanza, with them earning $16 million from post-birth baby prod­uct endorsements, a birth special for the E! network and even a post-birth weight-loss deal for a big-name diet company. But Kanye didn’t want any part of it, accord­ing to the insider. “He doesn’t care about money – he refuses to sell his baby.”

Meanwhile, the fam­ily momager’s new show “Kris” has been slammed by crit­ics, with one calling it “unwatchable” and another blasting it as “horrible, boring and self-involved.” As The ENQUIRER has re­ported, Kris, 57, is also plagued by ongoing boozing and cheating allegations as well as her looming divorce battle from Bruce Jenner, her husband of 22 years.

Her daughter Kourtney, 34, isn’t faring any better. She was recently slapped with a paternity lawsuit filed by male model Mi­chael Girgenti, who claims that he’s the true father  of her 3-year-old son, Mason. Girgenti charges that he and Kourtney en­gaged in a torrid affair while she and longtime beau Scott Disick were on the outs. Kourtney claims they never had sex.

“Kourtney is inconsolable, and the lawsuit is creating more tension be­tween her and Scott, who already have a highly volatile relationship,” said the insider.

“Kourtney lashed out at her mom, screaming that she’s sick of living her life in the spotlight and that this lawsuit never would have happened if they didn’t make money off selling their private lives.

“Kourtney is ready to bail on the whole family business. She’d be content to be an anonymous stay-at-home mom.”

AND KHLOE, 29,  is said to be “on the verge of a breakdown” over recent claims that her husband of nearly four years, basketball player Lamar Odom, had a six-week affair this summer with lawyer Polina Polonsky. That comes hot on the heels of a published report charging that he also cheated with Jennifer Richardson, a woman he met in a strip club.

The scandal just adds to Khloe’s heartache after her struggles with infertility, get­ting axed from her “X Factor” hosting gig and seeing her spinoff show, “Khloe & La­mar,” put on indefinite hiatus.

The cracks in the once-tight family were evident at Kylie Jenner’s recent 16th birthday bash at the Mal­ibu restaurant Nobu on Aug. 10. Kris and Bruce were there, but came and left separately. Khloe brought two bodyguards but not Lamar. And Kim was noticeably absent, along with Kanye and baby North. But Kourtney, Scott and their two kids did turn up for the celebration despite their recent problems.

“The tide has completely turned against the Kardashians,” noted the source.

“Kris always referred to her clan as America’s royal family, but now they’re more like a Greek tragedy.”