The poster promoting the show features a woman wearing a bra, and the text of the advertisement urges women to find a way "to your man's heart" by driving to the show, which features "lots of boys' toys".
Hewitt is also the minister for women. In a closed briefing for journalists, she is reported to have crticised the ads, describing them as "old-fashioned rubbish".
"As minister for women, I find this poster pathetic. We all know that sex sells, but haven't we got past 'boys with toys'? In terms of consumer power, women are increasingly talking the driving seat, but this looks like something out of the 1950s, rather than an ad for a modern motor show," she is reported to have said.
Her comments have caused a stir in the media as Hewitt is the minister responsible for the motor industry and is also supporting attempts to encourage 50,000 female engineering and technology graduates to take up engineering vacancies in the UK.
A spokesman for the British International Motor Show said: "We regret any offence taken by Patricia Hewitt and none was intended."
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