Claire Perry, who is close to Chancellor George Osborne, used to the description twice on Radio Five Live before being reprimanded by host Anna Foster.
“Claire I’m going to have to stop you using that analogy,” the presenter said.
“At eight minutes past seven on a Sunday morning it risks causing offence, so let’s move on from that.”
Ms Perry, 48, who used to work at Bank of America, immediately said: “I’m so sorry, I’m so sorry.”
She had been describing the culture she found in banking and told the programme: “It’s the most testosterone filled, you know, big swinging dick culture you’ve ever seen.”
Mrs Perry was later forced to apologise again on Twitter after one angry parent complained to her that his children heard it.
“Trading floor term but quite right to tell me off,” the Devizes MP tweeted in response.
It’s not the first time the mother of three has landed in controversy. In March, she attracted headlines after claims that she swore at a Eurosceptic Tory MP Douglas Carswell in the Commons. She also clashed with Commons speaker John Bercow after she was not called to speak in a Commons debate earlier this year.