The head of the Consumer Product Safety Commission says the number one consumer rip-off is the Federal government.

"It's costs are excessive," S. John Byington said in a letter to all Republicans in Congress. "It's rigidity is strangling our capacity to govern in a responsive and responsible manner."

Byington, a Republican who will be leaving his chairman's post at the end of June, wrote the letter to encourage support for President Carter's proposed plan to revamp the Civil Service system.

A controversial leader of the beleadured CPSC, Byington is credited with making major organizational changes in the agency, and streamling its operations.

He was, however strongly criticized by a civil Service Commission report which accused him of violating several Civil Service canons in his reorganization efforts.

"As one of the last remaining senior Republican managers in the United States government," Byington wrote, "I urge you and other Republican members of Congress to unite with the Democratic majority to pass the essence of Mr. Carter's proposals. I fear this critical initiative will fail without strong bipartisan support."

Byington said "I applaud the plan proposed by President Carter and his Task Force on Civil Service Reform."

The Senate Governmental Committee and the House Post Office and Civil Service Committee have both completed hearings on the proposed reforms suggested by Carter and Civil Service head Alan (Scotty) Campbell.

The program is in two phases. The committees are studying some of the changes which must be made through legislation. The second part of the reorganization involves a reform plan decided on by Carter and unveiled in a Rose Garden ceremony last week.

That portion is sent to Congress for review, and barring suggested changes automatically goes into effect in 60 days.

The reorganization calls for the dismantling of the Civil Service Commission and creation of an elite corps of some 10,000 managers who would have greater job flexibility than has ever been afforded civil servants, but at the same time sacrifices some of their job protection.