Layla Moran, MP for Oxford West and Abingdon, has admitted smoking cannabis at university.
The Mirror reported on the Liberal Democrat MP's appearance outside parliament with protesters looking to legalise medicinal cannabis, where she admitted taking the drug.
When asked to elaborate by BBC Oxford she said: "I see no reason to lie about having smoked cannabis at university, as I’m sure many of my fellow parliamentarians did.
"I do think the public are sick and tired of MPs pretending to not be real people.
"And if this revelation helps raise the profile of what is a vital issue for sufferers of chronic pain then all the better."