(CNN) - Rep. Mike Castle who lost the Republican Senate nomination in Delaware has decided not to launch a write-in bid for the seat.
"While I would have been honored to represent Delaware in the U.S. Senate, I do not believe that seeking office in this manner is in the best interest of all Delawareans," Castle said in a statement released Wednesday night.
In the statement Castle declined to endorse either candidate now running.
Castle had until tonight to decide if he would launch a write-in bid.
The GOP nominee Christine O'Donnell will face Democratic nominee Chris Coons in the general election in November. O'Donnell and Coons will face off in a CNN debate at the University of Delaware on October 13th.