The panel said Representative Tom DeLay of Texas, the House majority leader, offered to endorse Nick Smith's son in a Congressional primary if he would support a measure then teetering on the edge of defeat, the New York Times reported Friday.
Smith is a fiscally conservative Republican from Michigan.
The panel recommended no further action against DeLay or two others it also admonished, Smith and another Michigan Republican, Candice S. Miller.
Smith was admonished for "speculation and exaggeration" and for "making public statements that risked impugning the reputation of the House." The report said that contrary to his claims, he was never offered $100,000 or any other sum for his son's campaign.
Miller was admonished for promising not to support Smith's son because of the vote, an action the panel called an "unprovoked threat of retaliation."
Despite pressure to support a Medicare spending bill, Smith voted against it. His son has since lost his primary bid.