Democratic lawmakers and abortion rights organizations have opened an assault on Rep. Paul Ryan’s support for a controversial bill requiring doctors to perform an ultrasound on a woman before performing an abortion to ensure she can see the fetal image.

Abortion foes have fought for versions of the measure around the country, in the hopes of dissuading women from going through with abortions, while critics see it as unnecessary and intrusive.

"House Republicans — of which Paul Ryan is a leader — would shrink government so small it can only fit under the door of a woman's doctor's office," Rep. Nita Lowey told BuzzFeed Saturday. "This proposal to mandate a potentially invasive procedure is just outrageous to me and millions of other women who don't want the government interfering in private medical decisions."

Donna Crane, policy director for NARAL Pro-Choice America, called the bill “terribly un-American.”

“In this country we don’t force people to undergo medical procedures just because a politician says to,” Crane said, adding that the bill is “one of just a number of terrible positions” on women’s rights issues.

Romney Saturday formally announced that he was tapping Ryan as his vice presidential running mate, a move that delighted conservative supporters of Ryan.

Ryan is one of more than 60 lawmakers who have signed on to the Ultrasound Informed Consent Act in the House.

Authored by Rep. Jim Jordan, a leader of the House’s conservative wing, the House bill is a less invasive version of a Virginia bill mandating "transvaginal" ultrasounds that sparked a national controversy earlier this year.

Somewhat coincidentally, Romney announced Ryan as his running mate while on stage with Virginia Gov. Bob McDonnell, a was a strong supporter of the state bill who backed off it amid national controversy.

Although the bill does include an exemption for cases in which a woman’s life is at risk, it requires the doctor to provide an explanation in her medical records regarding the circumstances of the life threatening situation.

The bill would also provide the Justice Department with the authority to bring civil actions against doctors who do not comply with the law.

Conservatives have long hailed Ryan not only for his fiscal proposals but also his opposition to abortion and key gay civil rights measures long sought after by progressives.

Concerned Women for America president and CEO Penny Nance Saturday praised his record on social issues saying in a statement that Ryan "is an energetic and solid social conservative … he has tirelessly supported the unborn and voted in favor of a federal marriage amendment.”