Women's rights campaigner Jasvinder Sanghera is now urging other victims of harassment to speak out.
Ms Sanghera has disclosed that she was the woman who lodged a complaint against the former Liberal Democrat frontbencher Lord Lester of Herne Hill.
The 82-year-old peer is facing the longest suspension in modern parliamentary history after the Lords' Privileges and Conduct Committee found he groped her and offered her "corrupt inducements" to become his mistress.
Lord Lester, a prominent QC, has strongly denied the allegations, saying they are "completely untrue".
Ms Sanghera, who was not named in the report, waived her anonymity in an interview with The Times to say that she had made the complaint to establish that "what he did to me wasn't acceptable and wasn't honourable".
She said: "There needs to be a system in place that will give other victims the confidence to complain and to feel supported in doing so."
Ms Sanghera, a campaigner against forced marriage, had been working with Lord Lester on the passage of a parliamentary bill when the alleged incident occurred in 2006.
She said his conduct "made me feel physically sick", but at the time she felt there was little she could do.
"I was acutely aware of the power imbalance. If I'd said anything, who would believe me?" she said.
She finally lodged a complaint in November 2017 and said the rise of the #MeToo movement led her to hope that "by speaking out, victims were creating a climate in which people were more willing to listen".
Peers are expected to vote on Thursday whether to accept the committee's recommendation that he should be suspended to June 2022.
In its report, the committee upheld a finding that Lord Lester had breached the Lords' code of conduct "in failing to act on his personal honour by sexually harassing the complainant and offering her corrupt inducements to sleep with him".
According to her statement to the commissioner, Ms Sanghera said the peer had told her that if she slept with him he would make her a baroness "within a year", but if she refused he would ensure she never gained a seat in the Lords.
The committee said: "Lord Lester made a dishonourable promise backed by a dishonourable threat."
Ms Sanghera, 53, founded the charity Karma Nirvana and was made a CBE in 2013.
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