The harassment of women in Welsh politics has gone on for some years, a former government advisor has said.
Cathy Owens, who runs political consultancy agency Deryn, spoke out about the issue and said a politician once tried to get into bed with her while staying overnight at her house.
She was speaking to Sunday Politics Wales about the sexual misconduct scandal engulfing Westminster.
Welsh party leaders will discuss the issue at the Senedd on Tuesday.
Ms Owens said party leaders had been told about inappropriate behaviour but no action had been taken, adding some male politicians were "sexual predators".
She said: "I was very early on in my career, this was an elected representative, I made clear that nothing was going to happen, he was staying in the spare room, and sometime later [I remember him] coming into my bedroom and trying to get into my bed.
"In another situation someone has come into the taxi that I'm going home in."
Ms Owens said action needed to be taken to tackle the harassment faced by women in Welsh politics, saying the parties did not have the right procedures in place.
"These aren't random men flirting with women," she said.
"Thankfully we are talking about a small number of men who have used their positions and are sexual predators, they have used their position in politics knowing that the parties will protect them."
It comes as former AMs have also said the sexual harassment of women "goes on all the time" at the Welsh assembly.
Ex-politicians raised concerns about "a lack of procedures" and of colleagues "turning a blind eye to appalling behaviour".
The assembly said no formal sexual harassment allegations had been made against an AM.
One former AM spoke of a researcher who claimed she had woken up to find a male former assembly member undressing her.
The ex-AM also said they had to step in to physically stop a colleague from harassing another woman researcher.
Another former AM said it was difficult to report inappropriate behaviour in the assembly because it is such a small organisation.
"When you see someone behaving inappropriately, you're likely to know that person," they said.
"We tolerated things we shouldn't and turned a blind eye... but there wasn't a clear procedure for dealing with problems."
Finance Secretary Mark Drakeford said any allegations of sexual harassment at the assembly should be taken seriously and systems must be put in place to make sure such behaviour is not tolerated.
Finance Secretary Mark Drakeford said Ms Owens' experience made him "sick to the pit of his stomach" and such actions must "not be tolerated" in the future.
Labour said it had written to constituency secretaries and women's officers with specific guidance about reporting complaints of sexual harassment.
Plaid Cymru said it had put new infrastructure in place to deal with complaints more quickly and was reviewing its internal protocols and considering how it could strengthen them.
The Conservatives said they were "actively working with colleagues across the party to ensure that all the appropriate safeguards are in place to protect staff from harassment in all its forms".
A Liberal Democrat spokesman said: "There are clear guidelines on how to make a complaint and in cases where the complainant doesn't wish to disclose their identity the pastoral care officer can act as the de facto complainant".
UKIP said it was reviewing its safeguarding procedures to ensure the protection of all who work with the party.