Harriet Miers was expected to testify tomorrow before the House Judiciary Committee about the U.S. Attorneys scandal.  Today, her former boss, George Bush, told Miers not to appear [1]: 

President Bush ordered his former White House counsel, Harriet Miers, to defy a congressional subpoena and refuse to testify Thursday before a House panel investigating U.S. attorney firings.

"Ms. Miers has absolute immunity from compelled congressional testimony as to matters occurring while she was a senior adviser to the president," White House Counsel Fred Fielding wrote in a letter to Miers' lawyer, George T. Manning.