With two-thirds of screen time going to men, actresses in the UK turned activists this week and launched the Equal Representation for Actresses (ERA) campaign for gender equality in television, film, and theater. Dozens of actresses and sympathetic actors turned up for the speeches at BAFTA in London wearing the ERA 50:50 pin which has already been paraded on the red carpet by Emma Thompson and Emma Watson.

The crowd at the launch included Lily James, Gemma Arterton, Ophelia Lovibon, and James Nesbitt. Olivia Colman introduced the two founders of ERA, Polly Kemp and Elizabeth Berrington, who started the debate two years ago when a group of actresses met in London’s Soho and began to question the casting and creative decisions made by programmers and film-funders, which resulted in such an unequal share of screen time and employment opportunities. A British casting director confessed that in the last three years, she had found jobs for 393 men and 54 women.

“Tonight we come in peace but we mean business,” said Berrington, revealing plans to demand gender balance across drama and comedy slates by 2020. If change does not come “the cost to society is enormous,” she said. “Our culture and values are shaped from infancy by what we watch on screens.”

Little girls’ self-esteem peaks at eight years old, and the more they watch TV, the lower their self-esteem. Maybe that’s partly because children’s television has an even worse record than adult shows, with three male characters to one female.) A week’s study of the British children’s channel CBBC revealed a male to female ratio of six to one.

Even in Disney’s “Frozen,” co-directed and written by a woman, the male characters have more lines than the two starring sisters. And the older women get, the less, apparently, they have to say. A study of dialogue across 2,000 screenplays revealed that in the age group 32 to 41, men spoke 44 million words and women 18 million. By the time you reach the 42 to 65 age group men have 54 million words, and women 11 million. It most definitely does not reflect real life.

Actress after actress got up on stage to speak at the launch, often with black comic irony, about their own experiences on and off the casting couch. The rise of the #MeToo and #TimesUp campaigns has opened up the conversation about bullying and harassment. “We’re working with Time’s Up UK and will be a driving force behind its 50:50 by 2020 pillar of work,” said Deirdre Mullins of ERA.

Polly Kemp (“Four Weddings and a Funeral,” “Les Misérables) talked about actresses being bullied into compliance — “do what we say or we recast.” She recalled being informed that sex scenes would take place on a closed set, “and then by the third or fourth take the whole crew are there, staring.” Women are replaceable, suffering an ever-decreasing circle of employment, while men are “the jam in the sandwich,” getting all the supporting roles: the doctor, the politician, the detective. Women have a sell-by date, while men become characterful. As television production expands with Netflix, Sky, Amazon, and others, Kemp thought the solution was to create more female protagonists driving stories, so producers would “continue to employ actresses beyond their last fuckable day.”

What is “your last fuckable day” as an actress in the business right now? Mullins said she went to see a potential agent who said to her: “I’m only looking for skinny 17-year-old girls. It’s just hard to find older women work.” Mullins is 32.

“I went home and Googled Botox and filler — but frankly you’ve got to weigh that against fewer facial expressions,” she said, to much laughter from the thespian crowd. Mullins was delighted to see Frances McDormand’s Oscar-nominated performance in “Three Billboards Outside Ebbing, Missouri.” (“She was wearing her own face!”)

On television in the UK, Mullins has starred opposite Greg Davies, 49, in Channel 4’s “Man Down,” Sean Bean, 58, in “The Frankenstein Chronicles,” and David Schofield, 68, in “Father Brown,” proof of the yawning age gap between couples on screen. In real life, the average age gap between couples is two or three years. “I loved working with these actors,” said Mullins. “But we are the nation’s avatars.” What picture of normal relationships do those age gaps give?

Last year, women made up only 24 percent of protagonists in the top-grossing 100 movies, and ERA suggests that gender-blind casting and considering swapping male roles to female would help. The actresses all emphasized the need for more diversity, and for great drama scripts, written by women, for women. After all, it makes economic sense. In America, “The Handmaid’s Tale” and “Big Little Lies” triumphed at the Emmys and women’s stories are seen as big moneymakers, but the UK lags behind.

Although the audience ratings are often massive for woman-led dramas on British television (“The Crown,” “Doctor Foster”) or for a woman writer like Sally Wainwright (“Happy Valley,” “Last Tango in Halifax”), most series are still written by men. ERA says that UK TV commissioners are reluctant to use women writers and stick to the same old tried and tired gents. The BBC commissioned 32 male writers for series last year, and eight women. Channel 4’s record is even worse.

Many men are big supporters of ERA 50:50, including Nesbitt, David Tennant, and James McAvoy. The comedian Miles Jupp appeared self-deprecatingly as “one of those rare, middle-class, privately-educated, white males” on stage at the event to talk about television and radio panel shows, which are male heavy in Britain. Jupp presents Radio 4’s “The News Quiz,” and a few years ago he suggested they make the panel 50:50, which he thinks has much improved the show. The presenters’ statistics since then? Exactly 130 men and 130 women.

In the United States, Meryl Streep spoke up about supporting the 50:50 by 2020 initiative, but Mullins says that “there are no current plans for U.S. side growth or affiliation. First up we’re looking to professionalize the campaign here in order to sustain this level of work and progress,” she explained. “Currently no one is being paid a penny and lots of us are working almost full time on it — so we’re not looking to expand the remit until we can secure some serious funding. The future is looking very bright though — and with the incredible sense of energy and urgency out there at the moment, it really does feel like anything is possible. Watch this space!”