The Washington Post reported Wednesday that members of Congress inserted a provision in a classified annex to the $1.1 trillion government spending bill introduced this week that would restrict funding or authorization to transfer from one to the other.

The move is an unusual one for Congress, and the debate over it will be closed to a small circle because of the classified nature of the addendum.

President Obama, under considerable pressure from the left over the program’s civilian deaths and potential violations of international law, has for some time sought a way to distance himself from the controversial program that has come to be seen as his signature foreign policy and national security tool.