Paul Weyrich, co-founder of the Moral Majority, who once endorsed Romney, is among those calling on McCain to look beyond Romney, his former rival and past governor of Massachusetts, the Los Angeles Times reported.

McCain and Romney have made joint appearances and have exchanged kind words since Romney abandoned his own campaign for the nomination after the Feb. 5 Super Tuesday contests, the newspaper said.

In a newspaper ad, conservatives said Romney is "utterly unacceptable" as a vice presidential pick. The ad questions Romney's commitment to fight abortion and gay rights.

"To be clear, we all welcome anyone who has come around to the cause of life and family. However, Romney's actions as governor flatly contradict both the values widely associated with his faith as well as his pro-life and pro-traditional marriage campaign rhetoric," the ad reads.

The ad first appeared in Prescott, Ariz., where McCain was campaigning, and is expected to appear in other papers where the Arizona senator is on the stump, the newspaper reported.