Dame Laura Cox QC, who was appointed by the House authorities to investigate claims of bullying and harassment of staff, said there were “urgent and serious problems” in the procedures for dealing with such issues.
However, in a damning report she said it was “difficult to envisage” how solutions could be delivered under the current senior House administration.
“Amongst current and former staff alike there is an obvious pride and affection for the House and its status. Working there is, for many, a privilege - whether as a member of House staff or as an elected Member of Parliament - and there is an expectation of loyalty to the institution they serve,” she said.
“But that sense of loyalty has been tested to breaking point by a culture, cascading from the top down, of deference, subservience, acquiescence and silence, in which bullying, harassment and sexual harassment have been able to thrive and have long been tolerated and concealed.
“This is not to demonise the entire institution, but unacceptable behaviour by some, whether elected Members or House staff, inflicts damage on everyone and undermines the legitimacy and authority of the House of Commons. Parliament is diminished.”
Dame Laura, a former high court judge, was appointed by the House of Commons Commission to conduct an inquiry after BBC2’s Newsnight highlighted a series of allegations of bullying and harassment by MPs, including claims Speaker John Bercow bullied his former private secretary which he denied.
In her report, she said there was a need for a “broad cultural change” to restore the confidence of the staff and the wider public, which would require “a focus and a genuine commitment” by the House leadership.
“Having commissioned this inquiry, I fear that the House may fail those it is trying to help and sustain further damage to its reputation and to its credibility as an employer if this report leads only to another series of initiatives and process changes,” she said.
“A significant number of those members of House staff who came forward regard the status quo as untenable and express the view that ‘it will take several generations until the senior administration are capable of delivering the necessary changes’.
“On this basis, I find it difficult to envisage how the necessary changes can be successfully delivered, and the confidence of the staff restored, under the current senior House administration.”
Dame Laura said that she had been presented with a series of serious allegations of abusive conduct by both MPs and House staff, some of whom were referred to as “serial offenders”.
In line with her terms of reference, she did not name any of the individuals involved.
However she noted: “When reading this report some people may privately recognise their own behaviours in some of the alleged abusive conduct I have described.
“I would hope that a process of reflection leads them to consider what, if anything, they should now do in the best interests of the House.”
A spokesman for the Commons said: “Bullying and harassment have no place in the House of Commons, and the well-being of our people will always be our top priority.
“Staff must be confident that unacceptable behaviour will be dealt with seriously, independently and with effective sanctions.
“Urgent work has already been undertaken to improve internal processes - including the introduction of new confidential support services and helplines run by external, independent specialist providers and a clear pathway for the investigation of allegations.
“The findings of this inquiry will be taken into careful account”.