The new developments come as Vice President Dick Cheney has indicated the spy program was enacted as part of an attempt to strengthen presidential authority that has been weakened since Watergate and Vietnam.

• Vice President Dick Cheney: “Watergate and a lot of the things around Watergate and Vietnam, both during the 1970s, served, I think, to erode the authority I think the president needs to be effective, especially in the national security area. Especially in the day and age we live in … the president of the United States needs to have his constitutional powers unimpaired, if you will, in terms of the conduct of national security policy.”