Cynthia Nixon reveals if 'Sex and the City 3' not happening pushed her to run for office (Exclusive)

Cynthia Nixon is setting the record straight on Sex and the City 3!

Just one day after the 51-year-old actress announced she was running for governor of New York, ET caught up her while she was en route to her first campaign event in Brooklyn, New York, on Tuesday. She told us exclusively that the third installment of the Sex and the City movie not happening had nothing to do with her gubernatorial bid.

"Not at all," Nixon, who portrayed Miranda Hobbes in the SATC series and movies, replied when we asked if SATC getting shelved was "the final" push. "No!"

Nixon continued on, clarifying that her decision to run was actually in the works for nearly a decade.

"This is a decision that has been a longtime coming," she explained. "People have actually been asking me to do this for nine years."

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She tells ET that, so far, she's found her biggest support within the public school community. "[My biggest supporters are] other public school parents that I was fighting alongside with for better schools," she said.

Of course, she has also found support from her family, including her three kids -- Max, Samantha and Charles -- whom she shares with her wife, Christine Marinoni.

"I think they're excited on a certain level and dreading it on another," Nixon shared. "I think they are very proud. I think they are."

Nixon will challenge Democratic Gov. Andrew Cuomo in the state's Democratic primary in September.

Reporting by Darla Murray.

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