WGA members have authorized a strike if "WGA negotiators determine that a fair and reasonable contract cannot be negotiated with the networks and studios."
Dan Brown wrote the mystery "Angels & Demons" before his blockbuster "The Da Vinci Code," but after Ron Howard's adaptation of "The Da Vinci Code" became a huge worldwide hit, a seven-figure deal was made with writer Akiva Goldsman to turn the earlier novel into a sequel, Variety.com reported.
Production on the film is slated to begin in Europe in February.
Howard will direct the sequel and Tom Hanks will reprise his "Da Vinci Code" role of symbologist Robert Langdon in the thriller, which is slated for release in December 2008.
Producers Brian Grazer and John Calley, the studio, Howard and Goldsman are hoping to finalize the shooting script before next week's deadline.
Howard will shoot "Angels & Demons" as he supervises editing and post-production on his screen adaptation of Peter Morgan's play "Frost/Nixon," the trade paper said.
"Frost/Nixon" has also tentatively been scheduled for a late 2008 release.