Supporters of the Virginia ultrasound bill may have lost a key ally Tuesday evening when Governor Bob McDonnell (R) withdrew his unconditional support for the controversial legislation, according to The Washington Post.

The decision came after McDonnell's staff held a meeting with delegates and found the ultrasounds being more invasive than originally considered. Instead of previously backing any ultrasound bill that would reach his desk, McDonnell's spokesman Tucker Martin exhibited a notable change.

“Our position is: If the General Assembly passes this bill the governor will review it, in its final form, at that time,” Martin said in a statement.

The Virginia House postponed a final vote on the bill for a second consecutive day Tuesday afternoon. Both the state's House and Senate have already approved their versions of the bill.

According to the Post, a crowd of 1,200 men and women held a silent protests outside the state capital in Richmond Monday evening, wearing T-shirts that read "Virginia is for lovers, not probes."

The ultrasound bill would require a woman to undergo a medically unnecessary ultrasound by inserting a probe into the vagina to determine the gestation age of the fetus. A woman who declines to look at the ultrasound would have to sign a statement that would become apart of her medical file along with the printed image.

The legislation has been widely criticized for invading a woman's privacy, including by Comedy Central host Jon Stewart slamming McDonnell Tuesday evening.

Update: Virginia Governor Bob McDonnell issued a press release Wednesday afternoon, saying "no woman in Virginia will have to undergo a transvaginal ultrasound involuntarily."

McDonnell's statement comes after Virginia's House Republicans are expected to amend the bill that would make an ultrasound before abortion voluntary instead of mandatory.

This post has been updated from its original version.