British fashion designer Katharine Hamnett made history at London Fashion Week in 1984 by wearing an anti-nuclear war slogan T-shirt next to then-Prime Minister Margaret Thatcher – but that iconic moment nearly didn’t happen.

“I wasn’t actually going to go,” Hamnett said. “We all hated her.”

The designer continued: “But then I realised I had a photo opportunity. So I quickly made [the T-shirt] in the workshop and wore it.”

The T-shirt read ‘58% don’t want Pershing’ – a reference to a poll done at the time about Pershing nuclear missiles.

The fashion designer, 77, made her name with political and often contentious slogan garments, worn by the likes of Peaches Geldof and Naomi Campbell.

Four decades later, Hamnett has revived her T-shirt moment with a charity collaboration with Oxfam. The limited edition garments put the spotlight on the climate crisis and fast fashion, reading: ‘No More Fashion Victims’ – which she modelled on the Oxfam and Vinted ‘Style for Change’ runway.

The designer is known for her outspoken advocacy on sustainable and ethical fashion practices.

“The thing that’s really killing British fashion is Brexit, as you can’t export,” Hamnett said.

“I’ve won loads of awards, but the one that I was proudest of is the BKCC Export Award [the British Knitting and Clothing Export Council Award, which she won in 1988].

According to Hamnett, if British labels want to get their clothes out to fashion-loving countries like France and Italy, “We need exports to survive. Brexit has killed that. We need freedom of movement, otherwise pioneering British fashion is impossible.”

In 2011 she was made Commander of the Order of the British Empire (CBE), but earlier this year she posted a video online in which she threw her award into a wheelie bin, while wearing a top saying: “Disgusted To Be British.”

In the clip she emerged from her house and said to the camera: “I’m disgusted to be British for our role in genocide in Gaza. This is my CBE. It belongs in the dustbin, with Sunak and Starmer.” According to the Cabinet Office, it is possible to renounce an honour, but a recipient still holds it until the King agrees to annul it. As a result, placing a CBE in the bin is only a token gesture until formal action is taken by the monarch.

When asked what advice Hamnett would give to young people trying to break the fashion industry, she exclaimed: “Don’t do it – it stinks!”

“Most design jobs can be taken over by AI now,” Hamnett lamented. “I could literally ask AI to design a collection from the style of Katharine Hamnett in 1984 and it would be done in five minutes – with the the patterns cut as well. So you’ve got to be really thinking.”

So what does Hamnett think about the state of fashion today?

“The BFC [British Fashion Council] has made progress and it all helps, but the fact remains, 50% of our fibres are plastic – polyester,” she said.

She’s a big proponent for using organic cotton, and said: “Organic cotton makes an unbelievable difference to the planet and the people that grow it. It takes them out of abject poverty, allows them to feed, how their families, educate their children, afford healthcare. All cotton should be organic.”

When asked what she hopes London Fashion Week would do differently to progress as a sustainable event, Hamnett simply declared: “Slick it the f*** up.”