British Prime Minister Theresa May has promised to take action to protect government staff against sexual harassment, as allegations grow of inappropriate behavior by male members of parliament (MPs).

A series of claims about the behavior of senior politicians have emerged in recent days, after the Harvey Weinstein scandal encouraged women in all professions to share their experiences of inappropriate sexual conduct.

At present, women who work for U.K. politicians are effectively self-employed and have no formal procedure to air grievances against their employers.

In a letter to the speaker of the House of Commons, John Bercow, May wrote that the current set-up must change.

“It does not have the required teeth as contractually an MP does not have to follow the procedure. I do not believe this situation can be tolerated any longer,” May said in her letter Sunday.

Commons leader Andrea Leadsom said Monday that the Cabinet Office is now investigating specific allegations about whether individuals had broken the ministerial code.

So far, three MPs have been openly implicated in wrongdoing. However, media reports suggest a secret list on the messenger smartphone app WhatsApp is being used by women to warn each other about the predatory behavior of a much larger group of MPs.

The list is said to be shared by parliamentary researchers, secretaries, and aides who use it to identify politicians with a reputation for sexually inappropriate behavior.

Paul Goodman is the editor of center-right blog Conservative Home. He said in a blog post Tuesday that May faces a tricky choice should fresh revelations break.

“If she keeps any besieged ministers in place, she’ll be accused of stubbornness. Sack them, and she’ll be accused of panic,” the political analyst wrote.

Goodman added that employees close to May would likely be preparing a draft cabinet reshuffle as a contingency against any breaking allegations.

Brexit Minister Mark Garnier has admitted using a derogatory comment to his secretary and sending her to buy sex toys for his wife. He has been reported to the Cabinet Office but Garnier has denied any suggestion of inappropriate behavior.

Former cabinet minister Stephen Crabb has apologized for sending sexually explicit messages to a 19-year-old woman who applied to work in his Commons office. The 44-year-old devout Christian said he had been foolish but no sexual contact had been made. Crabb had previously been caught sending explicit messages to a different woman back in 2013.

The most recent revelation concerns a third Conservative MP, Defence Secretary Michael Fallon, who has admitted he repeatedly touched the knee of journalist Julia Hartley-Brewer in 2002.

Hartley-Brewer said in a statement Monday that she ended the matter by warning Fallon that if he did not stop she would “punch him in the face”. The journalist added that she did not feel like she was a victim of a sexual assault.