Things will be icy when Carrie & Co. hit the set of Sex And The City 2 later this year.

SATC co-stars Cynthia Nixon and Sarah Jessica Parker are allegedly on the outs, spies reveal in the August 17 issue of Star Magazine.

We hear Cynthia — who is engaged to marry her partner Christine Marinoni — is giving Sarah Jessica the silent treatment because the fashionista failed to participate in a gay rights rally in New York City last June.