According to bombshell legal documents, MARY RICHARDSON KENNEDY had to scrounge for cash in the final months of her life!

 “Mary was left to sometimes ask for $20 from the parents of her kids’ classmates to buy gas and groceries,” a source close to Kennedy told The NY Post.

These new shocking revelations come from a bombshell petition filed last week in Surrogate’s Court in Westchester County by Mary’s divorce attorneys, who charge Robert F. Kennedy Jr. failed to pay them a promised $278,000 in legal fees.

In the legal docs, they say RFK practiced a “scorched-earth litigation approach” that cast Mary adrift — cut off from a $20,000-a-month, court-approved credit card –unable to buy groceries, gas or receive medical care for their son.

As The ENQUIRER previously reported, Mary hung herself May 16 in a garage on her Bedford estate.

“Unfortunately, the last months of Ms. Richardson Kennedy’s life were full of daily financial challenges, directly attributable to Mr. Kennedy’s litigation tactics executed through his family office,” according to the petition.

As Mary struggled with alcoholism and depression, she was further humiliated by having her credit card declined at the both the local drug store and supermarket.

Her plastic was also no good and was denied by her son’s doctor, the source told the NY tab.

Under an October 2011 agreement, RFK Jr. was to continue paying his wife’s household and legal expenses.

Each spouse was to have a $20,000-a-month limit on a joint credit card, with the bills to be paid by the Kennedy clan’s money manager, the Park Agency.

Cutting her off was a tactic “to squeeze her and make her panic” as the custody of the couple’s four children, and division of assets — were being hammered out, the source said.

According to the court filing, Bobby also falsely claimed millions in joint assets as his own.