Blunt was one of four prominent Missouri politicians who called for Akin to drop out in light of the six-term lawmaker saying that in the case of a "legitimate" rape, the female body has ways of preventing a pregnancy.

While a number of top Republicans have called for Akin to step down, Blunt's urging is particularly noteworthy as he serves as presumptive GOP presidential candidate Mitt Romney's liaison to Congress. 

Akin has said he plans to remain in the race even though party leaders want him to stop campaigning. 

McCaskill has said Republicans leaders should not pressure Akin to step down. Democrats said Akin was their preferred candidate when he won the GOP primary to face McCaskill.