The Congress declares that it is essential—

((1)) to assure effective congressional control over the budgetary process;

((2)) to provide for the congressional determination each year of the appropriate level of Federal revenues and expenditures;

((3)) to provide a system of impoundment control;

((4)) to establish national budget priorities; and

((5)) to provide for the furnishing of information by the executive branch in a manner that will assist the Congress in discharging its duties.