IN a heartbreaking turn of events, pregnant Chelsea Clinton is trapped in the middle of a nasty family feud involving the soon-to-be grandmas of her baby.

Sources told The ENQUIRER that the former first daughter is des­perately trying to keep the peace between mom Hillary and her mother-in-law Marjorie Margolies, mother of her husband Marc Mezvinsky.

The ugly feud erupted after Mar­jorie, who hoped to become a U.S. Congresswoman, lost a May 20 pri­mary election and turned on Hillary for not using her clout to help her win, say insiders.

“Marc’s mom blames Hill­ary for her loss,” revealed a close source. “She thinks Hillary could have helped her win but avoided get­ting involved until the last minute and only gave her a lukewarm endorsement,” revealed a close source.

“She's furious bec ause they’ve been family since Marc married Chelsea.

“Meanwhile, poor preg­nant Chelsea has found herself caught in the mid­dle. She wanted her mom and mother-in-law to help decorate the nursery – and now they can’t stand each other!”

Added a concerned insider: “With Chelsea’s health and especially that of her baby, the last thing she needs is playing mediator to these two squabbling women. It should be a time of peace and harmony, not family infight­ing.”

Marjorie, who pre­viously served in the U.S. House of Rep­resentatives, is still seething over the May 20 election primary race, which pitted her against three other candidates in Pennsylvania’s 13th Congressional District.

It wasn’t until the final days of the campaign that Hillary finally showed her face at a fundraiser for Marjorie. Bill Clinton’s support also seemed half-hearted – he appeared at just two of her campaign events, say sources.

In an incredibly embarrassing ex­pose, “The New York Times” ran a piece on May 3 with the headline “A Clinton In-Law Seeks Office, but Where Are the Clintons?”

The story states: “The Clintons’ rela­tive silence has prompted awkward speculation in Phila­delphia that Mrs. Clinton does not want to be burdened by Ms. Margolies’s baggage in a state that could be pivotal to her chances in the 2016 presiden­tial campaign…”

The searing article points out that Marjo­rie had left Congress 20 years ago after her now ex-husband Edward Mezvinsky – also a former Congressman – was tossed into prison for fraud.

Mezvinsky, a former congressman and father of Chelsea’s husband, was indicted in 2001 and convicted on several dozen fraud charges. He served almost five years in federal prison.

Marjorie’s uphill campaign battle became even tougher when one of her opponents filed a complaint with the Federal Election Commission, accusing her of illegally using gen­eral elections funds in the primary.

Marjorie’s campaign called the claim “baseless.”

Now Hillary is returning fire – angrily rejecting Marjorie’s claim that she didn’t do enough in the campaign and blasting her as “unappreciative” and “a sore loser,” said the insider.

“Chelsea is just hoping the two will be able to put their dif­ferences aside and enjoy being first-time grandparents.”