Republican lawmakers in Virginia changed course on another piece of conservative legislation on Thursday, with the State Senate voting to suspend consideration of a bill that would define life as beginning at conception.

It was an abrupt reversal for Republicans, and came hours after a Senate committee voted to approve the legislation for consideration by the full body. There was broad speculation that Gov. Bob McDonnell was behind the move.

“This is a major disgrace for the Republican leadership,” said Don Blake, who runs the Virginia Christian Alliance, a conservative group that backed the bill. Republicans should have had the votes to pass the bill, he said, and the fact that they opted to suspend it raised suspicions of the governor’s involvement.

“Pro-life groups are concerned that the governor had a hand in this,” Mr. Blake said. A spokesman for Mr. McDonnell, a Republican who is mentioned as a possible candidate for vice president, did not respond to messages seeking comment.