RAMONA SINGER reportedly goes behind pal SONJA MORGAN's back to ink new contract as fate of Bravo TV skein hangs in the balance.

With a Friday deadline looming for the six Real Hosuewives of New York stars to sign new contracts or be fired, it’s emerged Ramona Singer and pal Sonja Morgan have fallen out after she “went behind Sonja’s back” and negotiated a deal without her, RadarOnline noted.

“Ramona agreed to her salary and shook hands, but then changed her mind at the last minute,” a show insider told Naughty But Nice Rob.

Complicating matters, the source said, “Ramona and Sonja are (now) not talking after Ramona went behind Sonja’s back and negotiated her deal without her.”

Singer, Morgan ,LuAnn de Lesseps, Carole Radziwill, Aviva Drescher and Heather Thomson have reportedly banded together over a salary standoff with Bravo, which has threatened to cancel the series as soon as Friday if the cast members do not sign their non-negotiable contracts.

Production on the sixth season was set to begin on WednesdayThe Hollywood Reporter reported, but none of the women have made themselves available for filming until the disagreement is settled.

There’s also a massive disparity between what some of the women earn: according to reports, Singer and de Lesseps pocket up to $500,000-a-season, while the three newest members — Radziwill, Drescher and Thomson — all earned just $60,000 for their debut year.