A Republican congressman has said that abortions should not be allowed even when the mother's life is at risk because of advances in "modern technology and science".

Joe Walsh of Illinois told reporters on Thursday that "you can't find one instance" where it has been necessary to perform an abortion due to the risk to the mother's life, citing medical advances.

The comments have prompted criticism, with some comparing Walsh's remarks to fellow Republican Todd Akin's infamous assertion that "legitimate rape" rarely results in pregnancy.

Walsh was speaking to reporters after defining himself as "pro-life without exception" during a debate with Democratic challenger Tammy Duckworth. Walsh was asked if he was saying it was never necessary to terminate a pregnancy to save a mother's life.

"Absolutely," he responded, according to WGN radio.

"With modern technology and science, you can't find one instance," Walsh said. He went on: "There is no such exception as 'life of the mother', and as far as 'health of the mother': same thing."

As Politico noted, Walsh's comments were particularly remarkable given that congresswoman Jackie Speier, a Democrat from California, spoke on the House floor 18 months ago about having an abortion because a pregnancy was threatening her life.

Medical experts note that there are some cases where the only option in the case of complications sustained during pregnancy is to abort the foetus. PubMed Health, the online medical library funded by the National Center for Biotechnology Information notes that some complications in pregnancy, such as an ectopic pregnancy, are life-threatening to the mother. "The developing cells must be removed to save the mother's life," the resource states.

Walsh's remarks also come after Todd Akin, the Republican Senate candidate for Missouri, made his infamous assertion that pregnancy as a result of "legitimate rape" is rare as "the female body has ways to try and shut that whole thing down".

Walsh, competing with Duckworth for the eighth congressional district in Illinois, is a Tea Party favourite who was elected in the 2010 mid-term elections. His "pro-life without exception" stance is shared by Mitt Romney's running mate Paul Ryan.

Akin ignored calls from both Democrats and Republicans to drop out of the Missouri race following his rape comments in August, although polling suggests he is a long way behind Democrat Claire McCaskill in the state.