Republican officials operating at the behest of the White House have begun seeking a possible successor to Attorney General Alberto Gonzales, whose support among GOP lawmakers on Capitol Hill has collapsed, according to party sources familiar with the discussions.

Among the names floated Monday by administration officials are Homeland Security Secretary Michael Chertoff and White House anti-terrorism coordinator Frances Townsend. Former Deputy Attorney General Larry Thompson is a White House prospect. So is former solicitor general Theodore B. Olson, but sources were unsure whether he would want the job.

On Monday night, Republican officials said two other figures who are being seriously considered are Securities and Exchange Committee Chairman Chris Cox, who is former chairman of the House Homeland Security Committee and is popular with conservatives; and former Attorney General William P. Barr, who served under President George H.W. Bush from 1991 to 1993 and is now general counsel of Verizon Communications.