Most fun Christmas sweaters are made of plastic and are “bad for the environment,” U.K.-based charities warned Friday, adding the time has come to ditch the festive staple in favor of “ethical” wear that is not a “threat to the natural world.”

A study by the Hubbub group found many Christmas sweaters are worn only once – and there are already 65 million stashed away in our wardrobes from previous years.

The research looked at 108 jumpers from 11 online and high street retailers and found 95 percent were made wholly or partly of plastic and to continue to buy and wear them shows scant regard for the planet.

Sarah Divall, creative partner at Hubbub, said consumers are often “unaware” of the damage their shopping may be causing to the environment, SKY News reports.

“We don’t want to stop people dressing up and having a great time, but there are so many ways to do this without buying new’, said Sarah Divall from Hubbub.

“Fast fashion is a major threat to the natural world and Christmas jumpers are particularly problematic as so many contain plastic. A lot of people are concerned about plastics in the oceans but they don’t realise that the stuff they are wearing also has plastic in it as well.”

12 million #christmas jumpers will be bought this year by Brits . And a whopping 2 in 5 of these will only be worn once. Skip the queues, save your money and help the planet by swapping with a friend or making a DIY costume yourself here https://t.co/z48XNL5NR0 pic.twitter.com/vOeC3fXAnV — Hubbub (@hubbubUK) December 6, 2019

Hubbub says people should borrow a sweater, buy something second hand or update a jumper they purchased in a previous year rather than buy new and encourage companies to stop producing “fast fashion items.”

“Have a Christmas jumper amnesty at work ahead of Christmas jumper day or swap with housemates to get a new look with minimal effort and no cost.”

Vintage retailer Beyond Retro has a business base of selling “ethical” Christmas clothing and has joined the call for consumers to put the environment ahead of festive cheer.

Store manager Diva Stoilova said retailers must “do their bit” to urge consumers to make environmentally sustainable choices.

“As we all know, our climate is in a bit of a crisis so we’re trying to do our bit, and it’s just much easier to buy something second hand or something ‘upcycled’. This way you don’t just produce new stuff to spend money on,” she said.

“We do encourage people to save their jumpers or we give them nice ideas of how they can restyle jumpers themselves in the future. We also encourage people to not use paper and instead use a biodegradable scarf to wrap their presents in. We are really trying our best.”