War has erupted between WHITNEY HOUSTON’s mom  CISSY and the singer’s one-time BFF ROBYN CRAWFORD over her secret tell-all diary!

With Cissy planning a bio about her daughter, Robyn has decid­ed to go toe-to-toe with her by penning her own book, say sources.

“There’s been bad blood between Cissy and Robyn for decades, and Robyn is afraid Cissy is going to trash her in her book,” re­vealed a close source.

“She doesn’t want Cissy to have the final say, so she’s going to write a book herself.”

A friend added: “Whitney’s death reopened old wounds, and a cat fight has broken out between Robyn and Cissy over their books. Whitney and Robyn were like Oprah Winfrey and Gayle King. They were super-close before Whitney married Bobby Brown – and Cissy always resented that.”

Whitney was a 16-year-old high school student when she met Robyn at a summer camp where they were both counsel­ors, and it led to an intensely close friendship. After Whit­ney’s career took off in the late 1980s, she made Robyn her personal assistant – and the two women lived together.

Author Kevin Ammons writes in his Whitney bio “Good Girl Bad Girl” that Cissy hated Robyn be­cause Whitney chose her, rather than Cissy, to take charge of her career.

Cissy demanded her daughter “get rid” of Robyn, believing lesbian ru­mors, even false ones, could de­stroy Whitney’s career, accord­ing to Ammons. Even though both Whitney and Robyn denied they were lesbians, Cissy said it wasn’t “natural” for the two to be so close.

One explosive confrontation involved all three women, writes the author. Robyn allegedly flew into a jealous rage after Bobby Brown sent the singer 400 roses while courting her.

Ammons claims Robyn ended up slapping Whitney, causing Cissy to scream: “What the %#@& did you put your hands on my baby for?”

After Whitney and Bobby wed in 1992, Robyn’s relationship with the star cooled off.

But following the superstar’s tragic death, Robyn wrote a tribute to her in “Esquire” magazine: “She knew I was never going to be­tray her. Now I can’t believe that I’m never going to hug her or hear her laughter again.”

British gay rights activist Peter Tatchell, who has close ties to the les­bian and gay community worldwide, said he has been told that Whitney was a “secret lesbian” and binged on drugs and alcohol because she was torn over her sexuality.

 “Whitney was happiest in the 1980s when she was with a female partner,” he told a re­porter. “They were so joyful together.

“She was pressured into the Bobby Brown marriage. It WAS a disaster.”