The U.S. Food and Drug Administration (FDA) has issued a new warning this week regarding the abortion pill RU-486 following the deaths of five women taking it, from bacterial infections.
But several conservative lawmakers are saying that this is inadequate, and want sales of the abortion pill halted until a further safety review has been conducted.
Republican Senators Jim DeMint, Sam Brownback of Kansas and David Vitter have joined forces to back new legislation.
The three lawmakers do however oppose abortion.
Another Republican Melissa Hart, is also sponsoring companion legislation.
The pill RU-486, also known as Mifeprex or mifepristone, is approved for terminating a pregnancy of 49 days or less.
Abortion opponents have fought vigorously to keep it off the U.S. market and have asked the FDA to revoke the approval.
According to the drug's maker, Danco Laboratories LLC.,more than 460,000 U.S. women have taken Mifeprex since it was approved in September 2000.
The deaths were announced by the company on Monday.
The three cases apparently involved a rare bacterium known as Clostridium sordellii.
One occurred during a clinical trial in Canada in 2001, while the other four were reported in California, two in late 2003, one in early 2004 and one in mid-2005.
Although the FDA has issued their own warning it does not consider the number of deaths as alarming, as they equate to about 1 in 100,000.
Dr. Steven Galson, acting director of the FDA's drug center, says as yet ' there are no alarm bells going off ', but they are watching the situation very closely.
The lawmakers are suggesting the death rate may be higher and that doctors and coroners may not have been aware of a potential link between a woman's death and the drug.
New York-based Danco plans to send a letter alerting physicians to the deaths and update warning information on the drug's label.