Conservative MP Anna Soubry says a trial by newspaper is taking place over sexual harassment claims that are sweeping through Westminster.
Ms Soubry, speaking on the The Andrew Marr Show, said those making complaints of a criminal nature needed to go to police or a relevant authority first.
Ms Soubry was addressing pornography allegations made against First Secretary of State Damian Green, which Mr Green denies.
"What we are having in relation to Damian, who I said should have been suspended so there was a proper inquiry, this would have formed part of that inquiry, and instead we are pretty much having trial by the newspapers," she said.
"And this is not acceptable"
Ms Soubry said the Prime Minister should call in Tory whips and find out what information they have on MPs.
"All the stuff that they know must be given to the Prime Minister and we must do things properly, and not behind the scenes, in some instances covering up, which is totally unacceptable.
"But also, when there are allegations, they go to the police or some other body immediately, so we don't have people's reputations trashed in the newspapers.
"Allegations of a criminal nature must go straight to the police."
Sir Michael Fallon's shock Cabinet resignation as Defence Secretary was cast in a new light as it emerged a journalist contacted Downing Street hours before his abrupt departure claiming that he had lunged at her and tried to kiss her on the lips in 2003.
Jane Merrick alleged in The Observer that the incident took place after a lunch when she was a 29-year-old junior political reporter.
She said: "I felt humiliated, ashamed.
Ms Soubry said that Ms Merrick approached her and Labour MP Harriet Harman before reporting the alleged incident to Downing Street.
She said she contacted No 10 about the matter ahead of Ms Merrick doing so.