A national anti-abortion leader has asked the Office of Congressional Ethics to investigate U.S. Rep. Mike Pompeo for alleged ethics violations during his re-election campaign.

Troy Newman is president of Operation Rescue. Last week, he made public documentation sent to the agency accusing the Pompeo of posting links to campaign material on his House website.

Pompeo’s office says it has found nothing that rises to a “material failure” to comply with all requirements.

What makes the allegations potentially significant is that they come from a prominent anti-abortion leader as Pompeo faces a tough primary challenge from former congressman Todd Tiahrt. Both conservative Republicans are staunch abortion opponents.

Abortion itself is not a campaign issue in the race, but anti-abortion forces here have grown into an important voting constituency.