The Conservative party is facing calls to suspend an MP whom it is investigating over allegations of rape and sexual assault. Rishi Sunak’s spokesperson declined to comment on reports that the party had hired a law firm to look into the conduct of a Tory backbencher after complaints by colleagues. It is understood that none of the alleged victims have made a formal complaint, but some Conservative MPs have reported the accusations to the police and the party. In relation to the complaints, first reported by TalkTV and the Sun, a Metropolitan police spokesperson said: “On October 28, police received allegations of serious sexual assault reported to have taken place on unknown dates at undisclosed locations. The reports were submitted via a third party. Officers are making inquiries into these allegations.” A formal investigation has not been launched. The allegations are the latest in a raft of sexual scandals faced by political parties in recent years. At least six Conservative MPs to have had the whip withdrawn or quit politics in the past 18 months over allegations of misconduct. One backbencher is currently under orders to stay away from parliament after being arrested on suspicion of serious sexual offences including rape. Labour MPs and Prospect, the trade union for some parliamentary staff, called on the Conservatives to take action on the latest case and suspend the whip, and ban the MP from parliament. Jess Phillips, the shadow minister for domestic violence, said: “I don’t understand how you can have people being investigated by your party or who are the subject of a police complaint who retain the whip. There is no explanation for that. I don’t want them wandering round parliament and I also don’t want them seeing constituents.” Chris Bryant, the Labour chair of the standards committee, said: “I don’t think it should be political parties investigating this type of complaint. It should be done confidentially, to a shared set of criteria, and the parties need to sit down and agree them.” Mike Clancy, the general secretary of Prospect, raised the issue of whether an MP facing allegations of sexual offences should be allowed to continue in their job in parliament while an investigation is ongoing. “The report that another MP has been accused of sexual offences raises important questions as to who knew what, when, and what have they done about it,” he said. “This MP remains free to visit the House of Commons and interact with staff despite these very serious allegations. This highlights yet again that there is no fit-for-purpose process in place to deal with this type of case and make parliament a safe place to work.” He added: “The Commons commission is finally looking into excluding MPs from parliament when they are under investigation for this kind of thing. That inquiry needs to be expedited.” Sunak’s spokesperson said he could not comment, but it was “right that any allegation of this matter is reported to the police and they’re able to take it forward”.