Former Alaska Gov. Sarah Palin (R) won't speak at a prominent gathering of conservative activists next weekend in Washington.

Palin will skip the Conservative Political Action Conference (CPAC) for the third straight year since  2008. She had skyrocketed to conservative stardom after serving as the GOP's vice presidential nominee in 2008.

Palin notified CPAC organizers Thursday morning that she wouldn't accept the plum slot as the conference's keynote speaker next Saturday night. David Keene, the head of the American Conservative Union, which organizes CPAC, said in a statement that Palin's absence was due to a scheduling issue.

Still, her decision to skip CPAC and its cattle call for possible Republican presidential candidates sends a strong message, especially coming from Palin, thought to be one of the party's top contenders for the nomination in 2012.

Other possible candidates who are set to speak include former Massachusetts Gov. Mitt Romney, former Minnesota Gov. Tim Pawlenty, former House Speaker Newt Gingrich, Mississippi Gov. Haley Barbour, Sen. John Thune (S.D.), Indiana Gov. Mitch Daniels and former Sen. Rick Santorum (Pa.).

CPAC this year has also been beset by controversy surrounding its decision to allow a group of gay conservatives, GOProud, to participate in the conference. Some top conservatives, including Sen. Jim DeMint (R-S.C.), another possible 2012 contender, pulled out of the conference.