RALEIGH -- Republican Sen. Richard Burr says he will try to block a White House attempt to replace the federal prosecutor overseeing a probe into two-time presidential candidate John Edwards. The North Carolina lawmaker said in a statement Thursday that he will support the nomination of Charlotte lawyer Thomas Walker once current U.S. attorney George Holding completes investigations into Edwards and former Democratic Gov. Mike Easley. Burr said Walker's political contributions to Edwards and Easley "represent a conflict of interest." Burr's Democratic counterpart, Sen. Kay Hagan, has also pressed the White House not to replace Holding but has not decided whether to block Walker's nomination. (Copyright 2009 by The Associated Press. All Rights Reserved.)