Two women whose accounts of sexual misconduct by Harvey Weinstein kick-started the #MeToo movement have warned that the allegations against the film mogul are “only the tip of the iceberg”.

Speaking two years after press reports first detailed abuse by Weinstein, his former assistant and theatre producer, Zelda Perkins, and Bafta-award-winning actor Rosanna Arquette, hailed a “profound transformation” but told the Guardian there were likely more revelations to come about high-profile men abusing their positions.

In October 2017, stories in the New York Times and the New Yorker prompted thousands of women to come forward with their accounts of sexual harassment and assault against a wide variety of perpetrators under the hashtag #MeToo. The movement had a far-reaching impact on how industries – from the arts to politics and business – dealt with allegations of abuse.

“I think [the Weinstein accusations] are the tip of the iceberg in what we are going to see and what will be revealed in the future – as we’ve just seen from Jeffrey Epstein and his horrible network that’s connected to so many powerful men worldwide,” said Arquette, who has alleged that the Miramax co-founder sexually assaulted her in the early nineties.

Perkins worked for Miramax in the 1990s and signed a non-disclosure agreement after she left the company when a colleague said they were attacked by Weinstein. She also said there were more stories to come about powerful men who have abused their positions.

“[Men like Weinstein] are everywhere and ultimately my call has not been so much about punishing these individuals – there are always going to be these individuals,” she said. “The real issue is that society and the system needs to change because currently the systems all work in favour of the powerful.”

Weinstein will face criminal trial in January 2020 for charges including rape and predatory sexual assault, all of which he has pleaded not guilty to. More than 80 women have alleged sexual misconduct by the producer over a period of four decades.

Both Arquette and Perkins said that while the publications of allegations against Weinstein had provoked some change for the better, they had not seen as much progress as they would have hoped for.

“It has been a profound transformation,” said Arquette. “It’s a massive worldwide wake-up call to men in particular to change their bad behaviour on a fundamental level.” But she added: “There are very, very powerful men in our business who feel sorry for him and that he lost his career and continue to behind the scenes figure out a way to support him.”

Perkins said: “People are beginning to speak and the water is stirring, but I don’t think that the changes are as big as people would have hoped in the two-year period. When you think about how shocking all the information that we have received – and are still receiving – is, unfortunately people have already been slightly inured to it.

“The trickle-down effect is absolutely there and things are happening but it’s a pendulum. The pendulum swung very, very far in one direction and then a lot of men got very upset and frightened and thought it was all frightfully unfair.”

Perkins said there would inevitably be a period of uncomfortableness. “There is when there is any big social change and I’m afraid, yes, we probably will lose some fantastically talented people [who have abused their power], but that’s the price that has to be paid to get back to zero and get proper equality.”

Asked why the Weinstein revelations had such a big impact, Arquette said: “We saw with the women who spoke out about Bill Cosby and Roger Ailes that the backlash can be horrendous. But for some reason, when the women came out against Weinstein the time was aligned with the stars, if you will, and somehow people were really ready and willing to listen in a way they hadn’t been before.”

The first use of the phrase “MeToo” to raise awareness about the prevalence of sexual assault and abuse against women was by the civil-rights campaigner Tarana Burke in 2006. “The sad truth is that it wasn’t until white women and particularly famous white women started using the term that it was taken up by the media in such a way,” said Perkins.

“Ultimately it doesn’t matter because I hope that the #MeToo movement has spread globally and I hope that all women feel that they own it.”