Constitutional provision giving Congress the right to make all laws "necessary and proper" to put its powers into effect. Used to justify wide expansion of government authority. Also called necessary and proper clause.

a statement in the U.S. Constitution granting Congress the power to pass all laws necessary and proper for carrying out the enumerated list of powers (Article I, Section 8 ).

a clause that allows Congress to exert its powers in ways not specifically outlined in the Constitution. For example, Congress has the power to pass laws relating to new technology that may affect other items covered in the Constitution, such as commerce. This is how the government stretches the Constitution to fit the changing times.