Representing Falsehoods

Legal representatives are generally not allowed literally to lie to the court, even if their clients so instruct them. Why is there no analogous prohibition on political representatives lying in Congressional proceedings? There is just such a prohibition against witnesses lying in Congressional hearings, after all. Having considered and dismissed several potential rationales for the disparity, I offer positive reasons to think there should be, since truth-telling is functionally important to the legislative process. I discuss some ways such a norm might be enforced within existing Congressional procedures, and I point to precedents in other countries where something similar has already been done.