John Bercow could face an inquiry into allegations of bullying in the autumn after Theresa May moved to open the Commons complaints system to historical allegations in one of her final acts of office.

The announcement coincides with the publication of an independent report exposing alleged sexual assaults by MPs against staff and “unacceptable” levels of bullying at Westminster.

Gemma White, QC, concluded that there was a “significant problem” after speaking to 220 members of staff. She found that alleged misconduct included MPs sharing explicit details of their sex lives with female members of staff.

The report said that some MPs routinely bullied their staff by shouting at them and humiliating them in front of colleagues. It quoted one member of staff who said