The US Republican congressman who caused outrage over his comments about "legitimate rape" has refused to abandon his senate bid in spite of pressure from presidential candidate Mitt Romney.

Six-term congressman Todd Akin said he would push on with his bid in the Midwestern state of Missouri, repeating that he "misspoke" during a disastrous television interview.

During a conversation on St Louis-based television station KTVI, Akin was asked if he would support abortions for people who have been raped.

He replied: "From what I understand from doctors, that [pregnancy] is really rare. If it's legitimate rape, the female body has ways to try and shut that whole thing down."

The backlash against Akin's comments was immediate and ferocious, with members of his own party pushing him to drop out of the race. Senator Roy Blunt issued a joint statement backed by all of Missouri's former Republican senators, claiming that Akin's resignation would "serve the national interest".

This statement was backed up by Romney, who said the congressman should "accept their counsel".

However Akin decided against stepping down, claiming he would bounce back after releasing an online apology video, which failed to stem the tide of criticism.

"I misspoke one word in one sentence on one day and all of a sudden, overnight, everybody decides, "well Akin can't possibly win'," he told former Republican presidential candidate Mike Huckabee on his radio show.

"Well I don't agree with that", he insisted.

Akin told another radio interview that he was in the race "for the long haul". However the collapse in support from his party colleagues has left him facing funding problems.

Meanwhile the stream of vitriol that was directed towards his apology video, entitled "Forgiveness", caused comments to be disabled.

See the video and footage of the controversial comments below: