A Tory politician faces being suspended from Parliament for six weeks after an independent panel found he sexually harassed a member of his staff.
The former employee told BBC Wales Rob Roberts repeatedly propositioned him and asked him to be "less alluring".
The Delyn MP said he apologised for a "completely improper" breach of trust "in the MP-staff relationship".
MPs must decide whether to back the recommended suspension, but Labour and Plaid Cymru urged Mr Roberts to resign.
A Conservative Party spokesperson apologised to the staff member for the "inappropriate and unwarranted treatment they were subjected to by someone in a position of authority".
Number 10's official spokesman said Mr Roberts had had the Conservative whip suspended, meaning he now sits as an independent MP in the Commons.
Earlier this year, the party closed its investigation into the Delyn MP saying he had been "rebuked" but would remain a Tory Member of Parliament at that time.
In his first interview, Mr Roberts's former employee said he had been left "uncomfortable," "shocked" and "horrified" by the MP's behaviour.
In June 2020, the ex-staff member decided to report the MP to Parliament's Independent Complaints and Grievance Scheme (ICGS) for sexual misconduct.
It is one of the first cases to be judged by the panel appointed to look at bullying and harassment cases last November.
On Tuesday the panel said Mr Roberts should be suspended for six weeks for breaching Parliament's sexual misconduct policy.
The complainant started working for the newly-elected Mr Roberts in early 2020, and said the MP made his "first advance" ten days later.
The staffer, who wishes to remain anonymous, told BBC Wales they were alone in a car together on a constituency visit when Mr Roberts said: "I find you very attractive and alluring and I need you to make attempts to be less alluring in the office because it's becoming very difficult for me."
The staffer says he found the comment "very uncomfortable" but "brushed it off" because the MP was "apologetic".
That weekend, he says Mr Roberts had dinner with his friend and "used it to ask permission to ask me out, or make a further advance".
Despite the friend "heavily discouraging him from doing so", the staffer said the next morning he looked in his work diary to see a "one-to-one booked with Rob".
In the one-to-one meeting, Mr Roberts told his staffer the advance he had made in the car was "something I would like to pursue, and if you would like to pursue that too it would make me very happy".
The staffer told BBC Wales: "I felt incredibly uncomfortable, shocked, pretty horrified.
"I tried to be very nice and said 'I really like you as a boss, but I think it's best our relationship stays professional'."
He says over the next few days Mr Roberts then exhibited "jealous behaviour".
"When I was having lunch with people he'd ask who they were, were they a boy or a girl?
"I'd arrange to have drinks with friends in the evening or dinner with my sister and he'd say 'why are you going for drinks with them and not me?'"
The employee says Mr Roberts had also made inappropriate remarks referring to the employee's sexuality.
After Mr Roberts invited him for drinks, and he said he was busy, the staffer says the MP then "booked drinks in the diary for the following Tuesday, outside of my hours, without giving me any go-ahead".
"That was the point I thought: 'I just can't come into work anymore.' Because it's not really appropriate behaviour, deliberately forcing me to spend time with him around him and alcohol."
'Very little job security'
Mr Roberts's former staffer said he was "in a constant haze".
"I had to find excuses just to get out of the room. I was constantly uncomfortable."
He said he had to decide "whether or not I was going to have to quit my job" and had a lot of "very difficult decisions to make" when he raised what was happening with the party whips.
"You're labelling yourself often in many ways as a 'troublemaker' with the party higher-ups and you don't know how the party is going to react.
"There is a reason there are so few of these complaints that come forward - the fear people have about what's going to happen to their career.
"I had very little job security and we had a pandemic around the corner."
The staff member ended up moving to a different role in Parliament, and has now left the organisation completely.
"I was put in a position where I had to leave my job and I shouldn't have been put in that position," he said.
The staffer first spoke to the ICGS's sexual harassment service in March, and pursued a formal complaint in June after being made aware of other allegations about Mr Roberts - even after the party whips had spoken to the MP about his behaviour.
In July 2020, messages seen by BBC Wales also showed Mr Roberts inviting a 21-year-old female intern who was working in Parliament to "fool around" with him in April.
The MP also repeatedly propositioned her after she told him she was struggling with her mental health.
The female intern told BBC Wales the messages had made her feel "really vulnerable".
The male staff member told BBC Wales Mr Roberts made comments about him during the independent investigation, "referring to me as 'attention-seeking', saying 'I'm trying to destroy his life and his career.'
"It is victim-shaming.
"A lot of the reason I've done this, and had to leave Parliament, is because I want to ensure that this doesn't happen to other people."
What does the report say?
In deciding that a six-week suspension from Parliament was appropriate, the panel said Mr Roberts had committed a "serious and persistent breach of the sexual misconduct policy".
The panel said the MP had taken "positive steps" to improve his behaviour, but had "demonstrated limited insight into the nature of his misconduct".
"We remain concerned that he does not yet fully understand the significance of his behaviour or the full nature and extent of his wrongdoing," the report said.
The panel recognised Mr Roberts - who had come out as gay after 15 years of marriage - had been "going through several challenges and significant changes in his personal life" but said these "do not excuse his sexual misconduct".
'Confidence to others'
Commenting after the panel's findings, the former staff member said: "I am very relieved that the report published today has found that Rob Roberts committed a serious and malicious breach of policies in place to protect staff from sexual misconduct and I will welcome the recommendation by the panel that he be suspended from the service of the House [of Commons].
"This has been a long process and I am grateful to the Commissioner, the investigator and the members of the various panels for their considered approach to the facts in this case.
"I hope that the House will now reflect on the findings in the report and take quick action to uphold the suspension. I am pleased that this has shown the complaints procedure does work and I hope it gives confidence to others."
The report says Mr Roberts "was informed of the sanction in March and appealed it, but his appeal was rejected on 17 May".
The male staffer says Mr Roberts also appealed the ICGS investigation on three grounds including claiming the "term of sexual harassment has been 'misused', he calls them 'romantic advances'" - but his appeals were rejected by the independent panel.
In June 2020 MPs voted in favour of forming this independent panel of experts to deal with bullying and harassment allegations against them.
The panel is entirely independent of MPs and sanctions decided by the panel can include the suspension or expulsion of an MP - which then require a vote in Parliament - as well as less severe sanctions that can be imposed directly by the panel.
'We've got this all the wrong way around'
If an MP is suspended for at least 10 sitting days by Parliament's Standards Committee this triggers a recall petition - which can lead to a by-election if it gains enough signatures.
However, sanctions imposed by this Independent Expert Panel, who judge more serious sexual harassment and bullying cases against MPs, do not automatically trigger the Recall of MPs Act 2015.
Chair of the Commons Committee on Standards, Rhondda MP Chris Bryant, said that was "manifestly unfair".
"I think it would be entirely dishonourable for a member to exploit that loophole and I think the government has to close it as a matter of urgency," he said.
"You would think that Parliament would want to have exactly the same set of rules for any kind of suspension from the House of Commons but, in particular, you would think that the sanctions against somebody for bullying and sexual harassment would be tougher even that for failing to register a gift, or something like that.
"But it looks as if we've got this all the wrong way around."
What has the Conservative Party said?
A Conservative Party spokesperson said: "We would like to apologise to the individual concerned for the inappropriate and unwarranted treatment they were subjected to by someone in a position of authority.
"There is no place for the behaviour they were subjected to and we praise their courage in coming forward.
"In light of the outcome of the Standards investigation Rob Roberts MP has had the Conservative Party Whip suspended."
The party launched its own investigation after BBC Wales published texts sent to the female intern and reported that Mr Roberts had admitted asking out a male parliamentary staff member.
The Conservative Party claimed it did not contact either staff member as part of its investigation because complaints were made by third-party complainants and had not come directly from the individuals involved.
Earlier this year the party closed the investigation saying it had "strongly rebuked" Mr Roberts for his "unacceptable" conduct, but that he would remain a Conservative MP.
What has the MP said?
Following the report, Mr Roberts issued a statement, saying: "In the first half of 2020, I was in a particularly challenging place personally and had taken the decision to leave my marriage of 15 years and come out as being gay.
"At around the same time, I asked a male member of Parliamentary staff to dinner in the hope of striking up a personal relationship.
"I recognise that this breach of trust in the MP-staff relationship was completely improper and should not have happened.
"I apologised at the time and do so again to the complainant but also to my colleagues, family and most importantly my constituents.
"I will continue to do my utmost to serve my constituency as I have over the past 18 months since my election, and this judgement will not alter my resolve to ensure that the people of Delyn get the assistance they need with pressing local issues.
"It is the greatest honour of my life to represent the constituency in which I grew up and have lived my whole life, and I will work tirelessly to restore any faith which has been lost by this ruling."
The MP has not commented on the messages sent to the female intern.
What is the opposition reaction?
Labour's deputy leader Angela Rayner said Rob Roberts "should resign immediately".
"The fact that such serious abuse doesn't automatically result in the recall of an MP is absurd and unjust and the Labour Party will support legislation to rectify that injustice," she tweeted.
"He should not be in his role for another single day more."
Labour party chair Anneliese Dodds MP added: "The Conservative government cannot dance around gaps in legislation if it is serious about upholding standards in public life.
"That is why we expect the government to take immediate action - Labour will support efforts to pass emergency legislation or measures to rectify this situation."
Plaid Cymru Westminster leader Liz Saville Roberts said the independent panel's report had highlighted the "sort of behaviour generally recognised, both within Parliament and outside Parliament, as being unacceptable".
"I honestly don't think that you can, with honour, remain in post as a Member of Parliament and I would join the calls for him to stand down," she said, also urging the Conservative Party to "consider how this looks".
"Just removing the whip from him under these circumstances, at a time when so many of us within Parliament have worked to make fairer and more honourable arrangements for members of staff, the Conservative Party cannot be satisfied by just doing this really mild tap on the wrist and say that everything can go on as usual, and nobody will really notice."