Emma Watson has donated £1m to a new campaign aiming to help those affected by sexual harassment.

The donation from the Harry Potter star to the UK Justice and Equality Fund comes as nearly 200 female British and Irish stars signed an open letter calling for an end to sexual harassment in the workplace.

Watson is one of the first donors to the fund, which was set up by the 190 women who signed the open letter, along with a group of 160 academics, activists and charity workers.

​Emma Thompson, Carey Mulligan, Saoirse Ronan, Gemma Chan, Keira Knightley and Watson are among the actors to sign the letter, which was published in The Observer.

The letter says Sunday’s Bafta awards ceremony is a time to “celebrate this tremendous moment of solidarity and unity across borders by coming together and making this movement international”.

“This movement is bigger than just a change in our industry alone,” it continues. “In the very near past, we lived in a world where sexual harassment was an uncomfortable joke; an unavoidable awkward part of being a girl or a woman.”

BAFTAs 2017 winners - in pictures Show all 14 1 /14 BAFTAs 2017 winners - in pictures BAFTAs 2017 winners - in pictures Joanna Lumley with the Fellowship award at the Virgin TV British Academy Television Awards 2017 Rex BAFTAs 2017 winners - in pictures David Haye presents the award for Best Sport for The Open in the press room at the Virgin TV British Academy Television Awards 2017 Ian West/PA Wire BAFTAs 2017 winners - in pictures Wunmi Mosaku with the Supporting Actress award for 'Damilola, Our Loved Boy' at the Virgin TV British Academy Television Awards 2017 Rex BAFTAs 2017 winners - in pictures Actor Adeel Akhtar poses with his Bafta for Best Leading Actor at the British Academy Television Awards 2017 Joel Ryan/Invision/AP BAFTAs 2017 winners - in pictures Sarah Lancashire with the award for Best Actress in the press room at the Virgin TV British Academy Television Awards 2017 PA BAFTAs 2017 winners - in pictures Phoebe Waller-Bridge with the award for Best Female Performance in a Comedy Programme in the press room at the Virgin TV British Academy Television Awards 2017 Ian West/PA Wire BAFTAs 2017 winners - in pictures Tom Hollander winner of Best Supporting Actor award for the 'Night Manager' at the Virgin TV British Academy Television Awards 2017 Rex BAFTAs 2017 winners - in pictures Presented by Katie Piper and Stacey Dooley, Winners of the Single documentary award, 'Teenage Prison Abuse Exposed' with the PANORAMA Production Team at the Virgin TV British Academy Television Awards Rex BAFTAs 2017 winners - in pictures Andy Worboys, Nicholas Bennett, Daniel Gordon, Andy Boag, Phil Scraton, Tim Atack and John Battsek, winners of the Single Documentary award for 'Hillsborough', pose in the Winner's room at the Virgin TV BAFTA Television Awards Dave Benett/Getty Images BAFTAs 2017 winners - in pictures Charlie Brooker with the award for Best Comedy and Comedy Entertainment Programme in the press room at the Virgin TV British Academy Television Awards 2017 Ian West/PA Wire BAFTAs 2017 winners - in pictures Victoria Derbyshire with her News Coverage award at theVirgin TV British Academy Television Awards 2017 Rex BAFTAs 2017 winners - in pictures TV presenters Ant and Dec pose with their Bafta for Best Live Event at the British Academy Television Awards at the Royal Festival Hall Joel Ryan/Invision/AP BAFTAs 2017 winners - in pictures Comedian Michael McIntyre poses with his Bafta for Best Entertainment Performance at the British Academy Television Awards Joel Ryan/Invision/AP BAFTAs 2017 winners - in pictures Nicola Shindler, Siobhan Finneran, Sarah Lancashire and Con O'Neill - Best Drama - Happy Valley Rex

It concludes: “If you have said ‘time’s up’, if the stories you have read in the papers have resonated and distressed you – join us in shifting the dial. Let’s make 2018 the year that time was up on sexual harassment and abuse. This is your moment too.”

Women attending the Bafta Awards in London last night have also said they will wear black on the red carpet, in a show of solidarity with the Hollywood-based Time’s Up movement.

Many are set to attend the ceremony with activists and campaigners rather than their partners. For instance, Gemma Arterton will be joined by former sewing machine operators Eileen Pullen and Gwen Davis, two of the 187 women who staged a three week walk-out from Ford’s Dagenham plant in June 1968 after learning they were to be paid 15 per cent less than their male counterparts.

The Baftas ceremony will be held at London’s Royal Albert Hall and will air from 9pm today on BBC1.