Missouri election law gave Akin until 5 p.m. local time (6 p.m. EDT) to take himself off the Nov. 6 ballot in the Senate race against Democrat Claire McCaskill.
Party leaders including Republican presidential hopeful Mitt Romney and Senate Republican leader Mitch McConnell had strongly urged him to step down.
But the Republican has vowed to stay in the contest, saying he represents a conservative movement that must be heard.
A staunch opponent of abortion rights, Akin claimed in a television interview on Sunday that women could not get pregnant from “legitimate rape” when asked about his opposition to abortion even in cases of rape and incest. REUTERSŒ