Several GOP senators are exerting pressure on the Food and Drug Administration to curtail illegal sales of unapproved and misbranded versions of mifepristone sold online, escalating the conflict between anti-abortion Republicans and the Trump administration over the abortion pill.

Sen. Bill Cassidy (R-LA), chairman of the Senate health committee, along with Sen. Lindsey Graham (R-SC) and three others, sent a letter to FDA Commissioner Dr. Marty Makary on Wednesday asking the agency for details on its enforcement actions against illegal sales of abortion pills.