Feminist writer Germaine Greer is under pressure to apologise after she suggested that British troops might take part in rapes if they are sent into Libya.
Patrick Mercer, Conservative MP for Newark and a former Army officer, accused Ms Greer of showing "extraordinary ignorance" in her remarks.
Ms Greer said on BBC1's Question Time programme on Thursday that all soldiers, in certain circumstances, will rape.
She was speaking during a discussion about allegations that Colonel Gaddafi had given his soldiers Viagra and ordered mass rapes as a weapon against rebels.
She said: "Rape is always present where you have slaughter and you don't have to have a government fiat (order) to do it. One of the interesting things you might ask about what happens if we send in ground troops, how will be sure they don't do a bit of raping in their turn?"
And she added: "All soldiers, in certain circumstances, will rape, regardless of whether they're ours or theirs or whose."
Mr Mercer, who was an Army officer for 25 years, said: "It shows extraordinary ignorance from someone who patently has no understanding of the conduct of disciplined forces, such as the British Army, Navy and Air Force.
"For her to confuse the British forces with irregulars from other countries is not only ignorant and foolhardy from her point of view, it is also insulting.
"She should stick to things she understands. I think an apology would be very much in order."
Ms Greer was not available for comment.