Actress Kate Winslet has said she has "bitter regrets" over "poor decisions" to work with certain film-makers.
The Oscar-winning Titanic star spoke of "directors, producers and men of power who have for decades been awarded and applauded" - but did not name names.
The 42-year-old appeared emotional as she accepted a special prize at the London Critics' Circle film awards.
Winslet has worked with producer Harvey Weinstein in the past and recently made a film with director Woody Allen.
Weinstein has been accused of multiple instances of rape and sexual harassment. The Shakespeare in Love producer has denied all allegations of non-consensual sex.
Allen has been accused by his adopted daughter Dylan Farrow of sexually abusing her as a child. He has repeatedly denied the claims.
Winslet, who was given her award for excellence in film by friend Jude Law, said she had been spurred to speak out by the Women's Marches that took place across the world earlier this month.
"As women around the world and from all walks of life marched last weekend... I realised that I wouldn't be able to stand here this evening and keep to myself some bitter regrets that I have about poor decisions to work with individuals with whom I wish I had not," she told an audience in London on Sunday.
"It has become clear to me that by not saying anything, I might be adding to the anguish of many courageous women and men," she continued.
"I know we all stand together in hoping that this moment in history paves the way for a transformed future for generation upon generation to come."
Winslet faced criticism last year for her response to a question about the claims made against Allen posed by the New York Times.
"As the actor in the film, you just have to step away and say, I don't know anything, really, and whether any of it is true or false," she was quoted as saying.
Her comments were referenced by Dylan Farrow in an opinion piece in which she alleged that Allen had been "historically protected" by "forces" in Hollywood.
"It breaks my heart when women and men I admire work with Allen, then refuse to answer questions about it," she wrote in the Los Angeles Times.
'End of days'
Winslet's honorary award came at the end of an evening that saw Three Billboards Outside Ebbing, Missouri take home three prizes.
The Oscar-nominated drama was named best film of the year, while its star Frances McDormand won best actress. A third award went to director Martin McDonagh for his screenplay.
Other award recipients included Hugh Grant, whose comic turn in Paddington 2 saw him named best supporting actor.
"Brexit, Trump and now me getting prizes," joked the Four Weddings and a Funeral star, suggesting his triumph symbolised "the end of days".
Grant went on to offer grudging thanks to Paddington 2 director Paul King and its producer David Heyman, suggesting the latter - the producer of the blockbuster Harry Potter films - had "needed a hit".
"My only sadness is that there aren't more of the other nominees here to look sad at this moment," he concluded, to laughter and applause.
'I could be watching Countryfile'
Best actor winner Timothee Chalamet, recognised for gay drama Call Me By Your Name, and Phantom Thread's Lesley Manville, who won best supporting actress, were also on hand to accept their prizes.
Chalamet thanked his co-star and "tongue-wrestling partner" Armie Hammer, while Manville joked that there were "worse ways to spend a Sunday - I could be watching Countryfile."
Both Manville and Chalamet have been nominated for Oscars for their roles.
Earlier this month Chalamet said he would be giving his salary for appearing in Woody Allen's next film, A Rainy Day in New York, to charity.
There were prizes too for Oscar nominees Daniel Kaluuya and Sally Hawkins, who were named British/Irish actor and actress of the year respectively.
Production designer Dennis Gassner, meanwhile, received the technical achievement award for his work on sci-fi sequel Blade Runner 2049.
The director of the year prize went to Sean Baker for The Florida Project, his funny and compassionate look at people living a breadline existence in America's Sunshine State.
Foreign-language film of the year: Elle
Documentary film of the year: I Am Not Your Negro
British/Irish film of the year: Dunkirk
Young British/Irish performer of the year: Harris Dickinson, Beach Rats
Breakthrough British/Irish filmmaker: Francis Lee, God's Own Country
British/Irish short film of the year: We Love Moses