Clothes swapping or “swishing” is set to become mainstream this year, a poll predicts, as consumers try to reduce their waste amid growing awareness of the environmental impact of fashion.

The research suggests 83% of Britons have at least six items of clothing in their wardrobe that they have not worn in the last year. Some admit to owning 200 items that they don’t wear.

Nearly a quarter of unworn items had been bought for a specific event such as a party or wedding and the owners had no plans to wear them again.

The study was carried out by the North London Waste Authority (NLWA) to coincide with the launch next week of its Wise Up to Waste campaign, which will encourage people to swap unwanted clothes at organised events.

Clyde Loakes, a councillor and the chair of the NLWA, said: “We’re asking people to dig [unwanted clothes] out and swap them for something they will wear. More mindful fashion consumption enables people to save money and will help tackle the climate emergency.”

The fashion industry has been heavily criticised for its environmental impact and for mixed messages including a £1 bikini on sale in the name of “women’s empowerment”.

More than 300,000 tonnes of used clothing goes into landfill in the UK every year. According to a report by the waste charity Wrap, if clothes stayed in active use for just nine months more than the UK average of two years and three months, it would reduce their carbon, water and waste footprints by up to 30%. Even the Vogue editor Anna Wintour recently called on consumers to “cherish” their clothes and pass them on.

The Charities Aid Foundation (CAF), meanwhile, is urging people to donate their unwanted clothes to charity shops rather than sending them to landfill. Its research found that 65% of people say they would buy fewer clothes in order to reduce waste, and only 14% said they were willing to accept some waste in order to keep up with the trends they liked.

Wendy Rigg, a fashion editor and stylist, said: “With vintage being so on trend, there couldn’t be a better time to start swishing. Clothes swaps provide the fun of fashion shopping without the guilt of waste.”