The actress - who reprises her role as Carrie Bradshaw in the big screen adaptation of the hit US TV series - filmed the original wedding scenes at New York's St. Patrick's Cathedral earlier this month, but has been told she must marry her fictional on/off lover Mr. Big for a second time.
A source said: "The wedding sequence with Carrie and Big is turning into a mess.
"They rushed through the shoot, and now it looks like most of it will have to be reshot at the New York Public Library in Bryant Park. It's a difficult scene to shoot, and the team isn't thrilled with the material they have. They are planning to get approval to head back into the library as soon as possible."