Members of the House of Lords should face medical examinations to see if they need to be barred from Westminster, a report into bullying and harassment in Parliament has said.

The investigation by Naomi Ellenbogen QC found most workers in the upper chamber did not lodge complaints about abuse because they feared reprisals, or thought nothing would change as a result.

The report found that one in five peers were considered to behave in an inappropriate or high handed way to staff, with one lord described as a “notorious bullying pervert” by a Westminster worker.

Ms Ellenbogen recommended that CCTV be installed in “hotspots for poor behaviour” like the Lords library and Table Office in order to try and deter abuse.

One employee said her backside had been grabbed by a peer when he was in the division lobby for a vote.

Staff suggested that health problems such as dementia could be contributing to the behaviour of some peers.

Ms Ellenbogen stated: “I recommend that the House agree and adopt procedures which will enable it to require members to attend for examination by an appropriate medical expert in the event that their state of health or behaviour is reasonably considered to be incompatible with continued attendance at the House of Lords.

“And, subject to that expert’s medical opinion, to require the relevant member not to attend the parliamentary estate (or to be appropriately restricted in his or her rights of access).”

A staff member is quoted in the report stating: “There are many repeat offenders. We also have to deal with situations where failing health and, possibly, dementia contributes to some of the more demanding behaviour.”

Ms Ellenbogen said: “Several contributors told me of a member who had been accused of pinching the bottom of a female clerk when passing through the crowded division lobby to vote.”

Branding the library and table office “hotspots” for inappropriate behaviour, the report said: “I recommend that CCTV be installed in both such areas to deter the continuation of such behaviour and provide a source of evidence of it, should it recur.”

Referring to an unnamed peer, dubbed “Lord Y” in the report, one staff member said: “He’s a notorious bullying pervert.

“You need to be careful and not be in a room alone with him.

“The onus is on you to protect yourself from them. The way the Table Office is designed, there is a door, a desk that you sit behind. It used to be open and they rearranged it so a member would stop leaning over to look down your shirt.”

The report said: “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.”

The report found a toxic culture of deference in the Lords.

The study said: “Significant concern was repeatedly raised regarding the conduct displayed by a substantial minority of members.

“Almost uniformly amongst those raising concerns, it was estimated that approximately 20% of members behaved in an inappropriate and high-handed way, with peers who were former members of the House of Commons being amongst the rudest.

“One contributor described a ‘hard-core’ of offenders.”

The study said: “I also received accounts alleging that each of two different individuals had groped an employee of a different gender.

“In one case, the alleged perpetrator was male and, in the other, female.

“Each allegation was serious and, manifestly, a source of considerable concern and distress to those who relayed it to me.”

The report was ordered after a wave of so-called “Pestminster” complaints in the wake of the #MeToo revelations.

A study into harassment and bullying in the House of Commons will be made public on Thursday.

Lord Speaker Lord Fowler said: “We have already made important improvements including introducing a Parliament-wide behaviour code, an Independent Complaints and Grievance Scheme and appointing a new conduct committee to which lay members will be appointed shortly, but there is still a great deal of work to do.

“Everyone deserves a workplace which has high standards of behaviour and mutual respect. Bullying and harassment have no place in the House of Lords.”

A Downing Street spokesman said: “The PM has said before that everybody working in all parts of Parliament deserves to be treated with respect and dignity and there can’t be any place for bullying or abuse anywhere in Westminster or any workplace.

“It is really important that the House leadership responds fully and properly to the concerns in today’s report.”