Protesters from the environmental action group Extinction Rebellion disrupted the third day of London fashion week, forming human blockades on roads around event venues to highlight the spiralling throwaway culture in the UK’s clothing market and to urge the British Fashion Council (BFC) to declare a climate emergency.

Groups made up of scores of demonstrators wearing black to mourn those whose lives have been devastated by environmental destruction caused traffic standstills for seven-minute intervals, unfurling banners saying “Rebel for life” and holding placards inscribed “Climate change = mass murder”.

Models and protesters mingled outside the main venue at 180 Strand in central London throughout Sunday, with lighthearted impromptu catwalks staged while leaflets were passed to motorists and bystanders warning of the catastrophic consequences of unsustainable growth and inaction over climate change.

Brighton BDS (@BrightonBDS) Taking a bit of time out for some #ExtinctionRebellion #London pic.twitter.com/Ve1unm91ni

Attendees outside the events said that ethical considerations had become fashionable, even mainstream, though campaigners contended they had always been trendy. “Minds in fashion are changing right now,” said Jonas Aucher, a French fashion student. “Fast-fashion brands like Zara have a huge impact, and the protesters are right that the industry has to change.” However, he added: “Recycled products are too expensive.”

Roxanne Murray, a stylist on her way in to an event, emphasised that most people were sympathetic to the need to be more environmentally conscious and that fast fashion needed to slow down. “We don’t have to buy new, cheaply made clothes,” she said. Shop at secondhand stores and wear vintage. Fashion isn’t just about you, it’s about all of us. If we all change together, it will have a great impact.”

Some fashionistas dismissed the protesters’ concerns, while others questioned whether climate change was indeed a man-made phenomenon. “We are in a diabolical situation and it’s too late to convince climate deniers,” said Caroline Vincent, a scientist. “We do need to engage, but we really don’t have the time: we must convince the people who already recognise there is a problem to do something about it.”

Mattha Busby (@matthabusby) Protestors now blocking road adjacent to Tate Modern for seven minute intervals, with some motorists turning their engines off and others defiantly revving pic.twitter.com/rFpGUI1dhW

The afternoon of civil disobedience by about 150 people passed peacefully with no arrests, as organisers stayed in constant contact with police on the ground and allowed emergency vehicles to pass when required.

Following one of the constructive conversations between protesters and drivers halted by the traffic, a liaison officer said the action had been a pleasure to police, adding: “You are getting the point across.”

Shortly after, one motorist who refused to turn off his engine during the stoppage shouted, “Fuck off back to Richmond. Can’t you move these soapy bastards?”

However, most people waited patiently and read the leaflets, and the sound of horns swiftly subsided as chants of “What do we want? Climate justice. When do we want it? Now!” echoed down the street.

Extinction Rebellion met the BFC on Tuesday to discuss the action it planned to take. The group also discussed how the industry body could use its influence to transform fashion into a force for cultural change that would stop the trend for excessive consumption and respond to the “urgent and existential threat of climate change”.

Molshree Vaid (@molshreev) This is your #lfw extravaganza served up with substance. The fab @lucysiegle opines about Swarm London Fashion Week at 180 The Strand #extinctionrebellion #techstylercrew pic.twitter.com/W7CoAoqd9Y

Clare Farrell, a fashion designer and co-founder of Extinction Rebellion, said: “We need to hold thought leaders and creators of culture to account. The fashion industry’s influence permeates deep within culture and radiates globally.

“While the fashion industry is not responsible for the unsustainable system it exists within, it is a key driver of global trends and a significant source of ecological devastation.”

She said global clothing consumption had doubled in the past 15 years, while utilisation – how often clothes are worn – had decreased by 36%, with total greenhouse gas emissions from textiles production, at 1.2bn tonnes annually, exceeding those of all international flights and maritime shipping combined.

“There are no signs that this is slowing, and events such as London fashion week contribute to and encourage this continued unsustainable growth,” Farrell added, saying that the fashion industry was the most influential on earth.

The BFC said it showcased British businesses engaging in sustainable practices and that it believed shifts within London-based brands could spearhead changes within the wider industry.

“We are committed to supporting businesses to do more to develop through green growth and our hope is that London fashion week becomes synonymous with responsible business in the years to come,” a spokesperson said. “We believe that more than any other capital, London has an opportunity to be a part of a cultural change around sustainable business practices that put creative product at their core.”