Katharine Hamnett is the queen of fashion jokes. "On the way here, I looked in the Uber mirror and thought to myself, 'If only I had Botox,'" the 76-year-old fashion designer says by way of introduction as we ride the elevator at The Mills Fabrica, a sustainability-focused incubator and co-working space near London's King's Cross, on a sunny October morning.

One could easily imagine that this line would have been printed on one of her famous slogan T-shirts, perhaps to protest society's ageist attitude toward older women. However, today Hamnett, wearing her trademark haircut and no makeup, along with a black top, jeans and sneakers, is more interested in spreading the word about the importance of voting.

"T-shirts and marches don't change anything if they are not followed by political engagement: people need to tell their representatives what they want and that if they don't feel represented, they will vote for someone else next time," she says in her typical no-nonsense style. "Your vote is the most powerful tool to get the world you want: use it or lose it." For this reason, Hamnett has created a new T-shirt with the words "Vote" and a QR code that leads directly to the government's voting page. "The goal is to encourage young people and women to vote," the designer emphasizes.

A sentiment echoed by the group of activists who, two days later, joined Hamnett on the set of British Vogue in East London, wearing the T-shirts. "It is very, very important that more young people participate in elections, especially with the new voter ID rule disenfranchising large numbers of young and marginalized people," says climate activist Dominique Palmer.

"Voting makes us active members of our society," adds Kalpana Arias, founder of Nowadays On Earth, an organization that connects people with urban green spaces. "I think we often forget that to really see the changes we want in the world, we have to actively participate in creating that future."

While millions of people have taken to the streets to demand climate action, led in recent years by figures like Greta Thunberg, it seems the message is not necessarily getting through to politicians. "The vote is about people power and being able to be heard," says Anjali Raman-Middleton, co-founder and director of Choked Up, a group fighting for clean air in London.

Ahead of the upcoming general election, Hamnett is in full campaign mode. She shows several prototypes of a tote bag with the slogan "I'd Vote Tax Deductible Childcare" as an illustration. "My idea is to start seeding a whole list of policies: tax-deductible childcare, student debt cancellation, nationalization of public services, Brexit cancellation." Although Hamnett returned to the UK for a few months for work, the outcome of the EU referendum is why she decided to move to Mallorca, Spain, in 2019: "I just wanted to get out of here."

Pushing for change within the political system is certainly a new strategy for Hamnett, who was famously photographed wearing a T-shirt that read "58 percent don't want Pershing" while meeting Margaret Thatcher at 10 Downing Street in 1984 to protest the deployment of nuclear missiles in Europe. Today, would he do something similar? "She would have to do something different: a good joke can never be told twice," he replies. "What would I do [now]? Would I bury the House of Commons under about 200,000 tons of garbage, so that you can only see Big Ben popping up at the top?"

Her ability to cut through the noise and communicate the messages that matter is undoubtedly one of her greatest strengths. "Katharine represents the power of storytelling," says Catherine Chong, climate economist and co-founder of Farms That Feed Us, a social enterprise that supports farmers. "Most people are not inclined to read scientific papers."

Born in 1947, Hamnett grew up during the "Cold War," meaning that politics was inevitably part of her growing up. The daughter of a diplomat, the designer lived all over Europe as a child, recalling the family having conversations with the faucets running in the bathroom to avoid possible surveillance that might have been installed in their home.

Although politics runs through her veins, Hamnett had never considered it as a possible career. "I wanted to be an archaeologist or a filmmaker," she recalls. "But my parents told me that to be an archaeologist I had to have a private income and that there were no female directors." When Hamnett found out that one of her schoolmates was attending Saint Martin's School of Art (now Central Saint Martins), she decided to follow her. "All teenagers are interested in fashion; it's like biological programming," she jokes.

Hamnett launched her eponymous brand in 1979, quickly achieving success with her utilitarian designs. "We were selling in some of the best stores in the world in 40 countries-not just T-shirts with slogans," she recalls.

Everything changed for the designer a decade later when she commissioned a report on fashion's environmental impact on the planet. "I thought there was nothing wrong with it, but of course it was all wrong: farmers dying from pesticide poisoning, millions of people working in factories in conditions worse than slavery," she says. In response, he adopted organic cotton, which was not widespread at the time, and brought production back to Europe (today his T-shirts are made on the Isle of Wight).

Has enough progress been made since Hamnett sounded the alarm? "There is a huge sustainability industry now-the conferences, the champagne. Everyone stands up and applauds at the end, and we carry on business as usual," he says wryly. "What we need is legislation."

Although change is slow, Hamnett has clearly made her mark on the fashion industry and beyond. "In the 1980s Katharine realized how disastrous the industry was and began to change her practices, to voice her opinions about what needed to change," reflects Liv Simpliciano, policy and research manager for the campaign group Fashion Revolution. "The same problems she was talking about-the lack of sustainable materials, the lack of adequate wages for the people who make our clothes, forced labor, the problems of waste-are all current."

The fact that Hamnett's T-shirts can be regularly spotted on the streets of the UK, even today, is proof enough of her lasting impact on new generations. "It is the epitome of wearing your values," says Joycelyn Longdon, founder of the educational platform Climate in Color. "I think we can all be inspired by it."

Hamnett is proud of her "Choose Love" T-shirt, which has raised 1.5 million pounds to help refugees and displaced people around the world. "It's the coolest T-shirt I've ever made," she says. "This morning I saw someone on a bicycle wearing the 'Choose Love' T-shirt. It makes me feel so good, because I think it's a philosophical stance that you should take to deal with anything."

But despite her accomplishments, Hamnett has no plans to rest on her laurels. The next thing to do? "If I could get Beyoncé or Rihanna to wear my 'Vote' T-shirt, that would be great," she smiles.