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.