We will submit legislation to the United States Senate which will... authorize the Congress to undertake judicial review of those signing statements with the view to having the president's acts declared unconstitutional.
Preparing a bill to allow Congress to sue the president in federal court; reported in "Sen. Specter preparing bill to sue Bush", NBC News (July 24, 2006).
Specter preparing bill to sue Bush - politics | NBC News[nbcnews.com]