Peers have overseen a culture of harassment and bullying in the House of Lords which has been hidden because staff fear reprisals, according to an official report released on Wednesday.

One in five members of staff in the upper house say they have experienced bullying or harassment, a seven month inquiry conducted by Naomi Ellenbogen QC has discovered.

Recommendations for the House of Lords include the installation of CCTV in harassment “hotspots” around the upper chamber, training for peers and a new head of the Lords to oversee any allegations which might arise.

It follows high-profile cases when peers including the Lib Dem Lord Lester have been found to have abused their position to sexually harass or abuse women.

According to the 132 page report, the prevailing culture and behaviours in the House of Lords have not been conducive to an open and supportive culture.

“Staff have bullied and harassed other staff. Members have bullied and harassed staff.

“On the whole, staff who have experienced bullying and harassment have tended not to complain, formally or otherwise, in the belief that nothing will happen and/or for fear of reprisal,” it concludes.

The report revealed that a staff survey last year found unprecedented levels of abuse towards staff.

“At 20%, the level of reported experience of bullying/harassment (excluding sexual harassment) is 9% points higher than across the civil service and marginally higher than the House of Commons (+2% points),” it read.

The report made 19 recommendations, which include installing CCTV in two areas where peers have been accused of abusing staff, particularly late at night – the library and in the tables office where peers can put down questions for ministers.

Others include improving peers’ behaviour with high-quality training and appointing a director general.

Ellenbogen said cultural issues in the Lords have enabled abusive behaviour to “flourish over a sustained period”.

She wrote there existed in the House of Lords “a culture of undue deference, fear and hierarchy that has put members and clerks at the top, and everyone else below”.

According to the report, that meant “staff can become institutionalised, bad habits can become entrenched, poor behaviour can go unchecked, urban myths can develop and beliefs which may once have been justified can survive and flourish when no longer warranted.”

There are currently 778 members of the House of Lords excluding 22 members who are currently not eligible to participate in its work. Of those, 661 are life peers, 91 are hereditary peers, and 26 are Church of England archbishops or bishops. Nearly three quarters of all peers are men.

The Sunday Telegraph reported in February that there had been 11 peers punished over harassment and bullying over the past six years.

Among the 11 was Lord Lester, who resigned from the Upper Chamber last year after author Jasvinder Sanghera accused him of sexual harassment. Following a critical report into his behaviour, he escaped punishment after the intervention of colleagues in the upper chamber, but has subsequently stood down from the House.

In response to the report, the Lord Speaker, Lord Fowler, speaking as chairman of the House of Lords Commission, said the Lords has already made important improvements.

“Bullying and harassment have no place in the House of Lords. This report is an important step in ensuring we, the commission, and the House of Lords administration, can work together to achieve that goal.

“It is because we are committed to this that we asked for this inquiry to be conducted. We are determined to address the issues the report highlights and to make the House of Lords better,” he said.

Another report into the treatment of those employed by MPs, rather than House of Commons staff, is due to be published on Thursday.

In a separate development, the minister for women and equalities, Penny Mordaunt, will on Thursday set out new plans to protect employees from sexual harassment.

Following scandals such as the Presidents Club dinner where hired hostesses were allegedly groped and sexually harassed, she plans involve provisions to strengthen the law, giving explicit protections to workers against harassment from third parties.